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Energy, Environmental, and Catalysis Applications

Sb2S3 Thin-Film Solar Cells Fabricated from an Antimony Ethyl Xanthate Based Precursor in Air
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  • Jako S. Eensalu*
    Jako S. Eensalu
    Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
    Max IV Laboratory, Lund University, Fotongatan 2, Lund 224 84, Sweden
    *Email for J.S.E.: [email protected]
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    Orcidhttps://orcid.org/0000-0002-4312-0227
  • Sreekanth Mandati
    Sreekanth Mandati
    Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
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    Orcidhttps://orcid.org/0000-0002-3317-271X
  • Christopher H. Don
    Christopher H. Don
    Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
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  • Harry Finch
    Harry Finch
    Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
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  • Vinod R. Dhanak
    Vinod R. Dhanak
    Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
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  • Jonathan D. Major
    Jonathan D. Major
    Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
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  • Raitis Grzibovskis
    Raitis Grzibovskis
    Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga LV-1063, Latvia
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  • Aile Tamm
    Aile Tamm
    Laboratory of Thin Film Technology, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia
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    Orcidhttps://orcid.org/0000-0002-0547-0824
  • Peeter Ritslaid
    Peeter Ritslaid
    Laboratory of Thin Film Technology, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia
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    Orcidhttps://orcid.org/0000-0002-3603-2237
  • Raavo Josepson
    Raavo Josepson
    Division of Physics, Department of Cybernetics, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
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  • Tanel Käämbre
    Tanel Käämbre
    Max IV Laboratory, Lund University, Fotongatan 2, Lund 224 84, Sweden
    Laboratory of X-Ray Spectroscopy, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia
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  • Aivars Vembris
    Aivars Vembris
    Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga LV-1063, Latvia
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  • Nicolae Spalatu
    Nicolae Spalatu
    Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
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    Orcidhttps://orcid.org/0000-0003-0234-2170
  • Malle Krunks*
    Malle Krunks
    Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
    *Email for M.K.: [email protected]
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  • Ilona Oja Acik
    Ilona Oja Acik
    Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
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ACS Applied Materials & Interfaces

Cite this: ACS Appl. Mater. Interfaces 2023, 15, 36, 42622–42636
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https://doi.org/10.1021/acsami.3c08547
Published August 28, 2023

Copyright © 2023 The Authors. Published by American Chemical Society. This publication is licensed under

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Abstract

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The rapidly expanding demand for photovoltaics (PVs) requires stable, quick, and easy to manufacture solar cells based on socioeconomically and ecologically viable earth-abundant resources. Sb2S3 has been a potential candidate for solar PVs and the efficiency of planar Sb2S3 thin-film solar cells has witnessed a reasonable rise from 5.77% in 2014 to 8% in 2022. Herein, the aim is to bring new insight into Sb2S3 solar cell research by investigating how the bulk and surface properties of the Sb2S3 absorber and the current–voltage and deep-level defect characteristics of solar cells based on these films are affected by the ultrasonic spray pyrolysis deposition temperature and the molar ratio of thiourea to SbEX in solution. The properties of the Sb2S3 absorber are characterized by bulk- and surface-sensitive methods. Solar cells are characterized by temperature-dependent current–voltage, external quantum efficiency, and deep-level transient spectroscopy measurements. In this paper, the first thin-film solar cells based on a planar Sb2S3 absorber grown from antimony ethyl xanthate (SbEX) by ultrasonic spray pyrolysis in air are demonstrated. Devices based on the Sb2S3 absorber grown at 200 °C, especially from a solution of thiourea and SbEX in a molar ratio of 4.5, perform the best by virtue of suppressed surface oxidation of Sb2S3, favorable band alignment, Sb-vacancy concentration, a continuous film morphology, and a suitable film thickness of 75 nm, achieving up to 4.1% power conversion efficiency, which is the best efficiency to date for planar Sb2S3 solar cells grown from xanthate-based precursors. Our findings highlight the importance of developing synthesis conditions to achieve the best solar cell device performance for an Sb2S3 absorber layer pertaining to the chosen deposition method, experimental setup, and precursors.

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Introduction

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The Sun imparts 10 000 times more energy to the Earth than humankind consumes. (1) Photovoltaics (PVs) provide direct clean renewable energy for restoring the ecosystem while sustaining humane living conditions. Increasing clean PV capacity requires stable, quick, and easy to manufacture solar cells from socioeconomically and ecologically viable earth-abundant resources. Emerging PVs are best suited for tandem cells with silicon and standalone semitransparent PV modules. As the absorber layer is the most critical component in PVs, a fitting inorganic absorber material should be sought. Antimony sulfide, a stable inorganic semiconductor (2) composed of abundant and environmentally benign S ($0.09 kg–1) and Sb ($11.4 kg–1), is an emerging PV absorber. (3) The covalent anisotropic 1D-ribbon structure (2,4,5) of Sb2S3 gives rise to its melting point of 550 °C, (2) allowing crystallization of the absorber below 300 °C. (5,6) Furthermore, Sb2S3 is an excellent thin-film solar absorber due to its direct band gap of 1.7 eV, (2,5) a refractive index in excess of 2.2, (5,6) and an absorption coefficient of 104–105 cm–1 in visible light. (4)
In addition, the single-phase composition, (2,7) facile synthesis by chemical methods, (4) long-term stability, and corrosion resistance (2,7) are the main qualities that Sb2S3 offers to the development of environmentally sustainable and affordable PVs. The efficiency of planar Sb2S3 thin film solar cells has risen from 5.77% in 2014 to 8% in 2022. (8,9) Enhancing their efficiency requires overcoming a large VOC deficit, (4) by amelioration of the intrinsic point defects inducing self-trapping in the absorber, (10) proper engineering of vertical grain growth, increasing the lateral grain size, (11,12) and interface engineering. Moreover, dewetting (6,13) and tuning of the precursor chemistry (6,9,11−16) must be addressed. In broad terms, the cutting-edge development of Sb2S3 solar cells has split into three main directions: maximizing solar cell efficiency for standalone applications, (9) maximizing the ratio of solar cell efficiency to absorber thickness targeting sustainable exploitation of antimony, (6) a critical raw material, (17−19) and development of semitransparent devices for use in building-integrated PVs or as the top cell in two-cell tandem PVs. (20,21) Further understanding in these directions depends on first-principles calculations and defect engineering studies.
Synthesis conditions largely determine the efficiency of Sb2S3 solar cells. (4) Antimony alkyldithiocarbamates have yielded highly efficient solar cells based on a chemically grown continuous and large-grained Sb2S3 absorber layer, (11,12) up to an efficiency of 7.1%. (22,23) solar cells in mesoporous TiO2 configuration based on Sb2S3 synthesized from antimony xanthate i.e. alkyldithiocarbonate have reached only 3.7% efficiency after sulfurizing the Sb2S3 absorber with thiourea. (24) Furthermore, xanthate-based planar Sb2S3 devices have not been reported. Considering the lower decomposition temperature of the xanthate-based precursor, it should be explored on a level with the carbamates. Previously, our group has reported that Sb2S3 films can be grown from antimony ethyl xanthate (SbEX) by ultrasonic spray pyrolysis only with additives such as thiourea or thioacetamide that shield the surface from oxidation during deposition. (25) Therefore, we endeavor to deduce how the PV absorber properties of planar Sb2S3 films grown from antimony xanthates differ from those grown from carbamates. Moreover, understanding the thermal and chemical history of the constituent layers of solar cells is vital to boosting the efficiency further by surmounting the many challenges ahead.
Hence, the aim is to bring new insight into Sb2S3 solar cell research by investigating how the bulk and surface properties of the Sb2S3 absorber, the current–voltage, and deep-level defect characteristics of solar cells based on these films are affected by the ultrasonic spray pyrolysis deposition temperature and the molar ratio of thiourea to SbEX in solution. Devices based on the Sb2S3 absorber grown at 200 °C, especially from a solution of thiourea and SbEX in a molar ratio of 4.5, perform the best by virtue of suppressed surface oxidation of Sb2S3, favorable band alignment and Sb-vacancy concentration, continuous film morphology, and a suitable film thickness of 75 nm, achieving up to 4.1% power conversion efficiency, which is the best efficiency to date for planar Sb2S3 solar cells grown from xanthate-based precursors.

Experimental Section

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The chemicals used in this study are listed in Table S1 in the Supporting Information.

Sample Preparation

Fluorine-doped tin oxide (FTO) covered 2.1 mm glass slides (MSE Supplies, TEC7) were cleaned by consecutively ultrasonicating in a bath of detergent water, 50/50 methanol–acetone, and isopropyl alcohol for 10 min, followed by immersion in boiling deionized water for 10 min. A compact TiO2 film was deposited by ultrasonic spray pyrolysis at 350 °C from a solution of 0.1 M titanium tetraisopropoxide and 0.4 M acetylacetone dissolved in ethanol, followed by heat treatment in air at 450 °C for 30 min to obtain anatase, as reported previously. (15,25,26) The average thicknesses of the active layers in the glass/FTO/TiO2 stack are 577 nm for FTO (density, ρ 7.0 g cm–3) and 77 nm for TiO2 (ρ 4.17 g cm–3) as calculated from XRF data. (27) The Sb2S3 absorber was grown using ultrasonic spray pyrolysis (USP) at a nebulization frequency of 1.7 MHz and a power of 200 W. The compressed air flow velocity was 3.7 cm s–1, and the solution flow rate was 11 μL cm–2 min–1 through a circular vertical nozzle (ϕ 100 mm) positioned 13 mm above the substrate surface, moving in a cyclical pattern over a 170 mm × 170 mm area (effective area 268 cm2). For the deposition temperature series, Sb2S3 absorbers were grown at temperatures of 200, 230, and 260 °C for 20 min from a solution of 90 mM thiourea (TU) and 30 mM SbEX dissolved in acetonitrile. Finally, the TU concentration series was deposited at a temperature of 200 °C for 20 min from a solution of TU/SbEX in molar ratios of 0.5, 1.0, 1.5, 3.0, 4.5, and 6.0 dissolved in acetonitrile at a constant 30 mM SbEX concentration. After the deposition of Sb2S3, the samples were heat-treated in a tube furnace at 270 °C for 10 min in nitrogen flowing at 1.1 cm s–1, at an average heating and cooling rate of 8 °C min–1. Solar cells were prepared by depositing a solution of 1 wt % regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) dissolved in chlorobenzene onto the FTO/TiO2/Sb2S3 stack by spin coating at 350 rpm for 4 s, accelerating at 2000 rpm s–1 to 3000 rpm for 20 s. P3HT was activated by heat treatment in a tube furnace at 170 °C for 5 min in nitrogen flowing at 2.1 cm s–1, at an average heating and cooling rate of 12 °C min–1. The stack was completed by thermally evaporating a gold back contact through a metal mask with ϕ 4 mm circles, thereby defining the active cell area as 12.6 mm2.

Characterization

The structure and phase composition were characterized by XRD (Rigaku Ultima IV, θ–2θ, Cu Kα1 λ = 1.5406 Å, 40 kV, 40 mA, step 0.02°, 5° min–1, Si strip detector D/teX Ultra) and Raman spectroscopy (Horiba Labram HR 800, ∼143 μW μm–2, 532 nm YAG:Nd laser). In accordance with best practices, (28) in this study we used the space group No. 62 Pbnm setting (ICDD #42-1393) for the Miller indexing of planes in Sb2S3 for which a = 11.09 ± 0.03 Å, b = 11.326 ± 0.017 Å, and c = 3.826 ± 0.015 Å and the covalently bonded ribbons lie parallel to the c vector, [001]. Optical spectra were measured using a UV–vis–NIR spectrophotometer (Jasco V-670, integrating sphere, air reference). Local elemental composition and morphology were measured with a combined energy dispersive X-ray spectrometer (Bruker spectrometer, ESPRIT 1.8, 7 kV) and scanning electron microscopy (Zeiss HR FESEM Ultra 55, 4 kV) system. Integral elemental composition was measured from a circle of ϕ 10 mm with a wavelength-dispersive X-ray fluorescence (XRF) spectrometer (Rigaku ZSX-400). Elemental composition was measured from the Sb Lα-line, S Kα-line, Cl Kα-line, and K Kα-line. The pure FTO substrate was analyzed as a homogeneous mixture of O (48.1 wt %), Si (33.2 wt %), Na (8.23 wt %), Ca (6.28 wt %), Mg (2.46 wt %), K (0.919 wt %), Al (0.73 wt %), S (0.0804 wt %), and Cl (0.0203 wt %).
X-ray photoelectron spectroscopy (XPS) spectra of a heat-treated Sb2S3 film, grown at 200 °C using TU/SbEX 3.0, were measured with a PSP Vacuum Technology hemispherical electron-energy analyzer equipped with monochromated Al Kα radiation (hν = 1486.6 eV). Spectrometer calibration was performed by measuring both the 3d5/2 and Fermi edge of a clean polycrystalline silver foil Ar+ sputtered under vacuum. (29) The spectrometer was operated with an overall resolution of ±0.1 eV. High-resolution XPS spectra were fitted with a Voigt (GL(X)) at a Gaussian:Lorentzian ratio tuned for an optimal fit. XPS spectra of heat-treated Sb2S3 films, grown at 200 °C with a variable TU/SbEX ratio, were measured with a SPECS PHOIBOS 150 2D-DLD hemispherical electron-energy analyzer equipped with a Mg Kα (hν = 1253.6 eV) source. (30) High-resolution XPS spectra collected with a pass energy of 50 eV and a step of 0.1 eV were fitted using CasaXPS (v2.3) software. Charging-induced offset in XPS spectra collected with SPECS PHOIBOS was corrected by calibrating with adventitious carbon (C 1s C–C, 284.5 eV). The Sb 3d, Sb 4d, and S 2p spin orbit split doublet peaks were separated based on literature by 9.40, 1.25, and 1.20 eV, respectively. (31) A Shirley background subtraction was applied in all XPS spectra. The width of the same species of doublets was constrained to be the same. XPS peaks were fitted with the Voigt-like symmetric Lorentzian (LA) line shape (1.53, 243).
Room-temperature current–voltage (I–V) curves of solar cells were measured with a factory-calibrated solar simulator (Wavelabs LS2, LED light source), a metal mask with an adjustable aperture area, and a source meter under AM1.5G, 100 mW cm–2 conditions. Temperature-dependent I–V curves were measured with a closed-cycle He cryostat (Janis CCS-150) using a halogen lamp. The position of the halogen lamp was calibrated to match the short-circuit current obtained with the solar simulator under AM1.5G conditions at room temperature as a starting point. The external quantum efficiency (EQE) spectra were measured without a white light bias using a monochromated light source at 0 V voltage bias (Newport 300 W xenon lamp, 69911 with a Cornerstone 260 monochromator), a digital lock-in detector (Merlin), and a factory-calibrated Si reference detector. The short-circuit current density (JSC) was integrated from EQE spectra under AM1.5G conditions.
Deep level transient spectroscopy (DLTS) analysis was conducted using a Phystech FT1230 HERA DLTS system connected to a Linkam HFSX350 liquid nitrogen fed cryostat with a measurement range of 85–275 K. The device back contact field was used to probe the deep level content by applying reverse and pulse biases of 4 and 1 V, respectively. A pulse duration of 10 μs was applied with resultant transients compared over three period widths of 4.8, 48, and 480 ms with values for the trap energies and capture cross section extracted from an Arrhenius assessment using the three period widths and a series of correlator functions. (32)
The ionization energy level value of the studied materials was determined by using a self-built photoelectron emission spectroscopy (PES) system. The system consists of a white light source (ENERGETIQ Laser Driven Light Source (LDLS EQ-99)), a monochromator (Spectral Products DK240 1/4 m), and an electrometer (Keithley 617). The measurements were carried out in a vacuum (∼2 × 10–5 mbar) at room temperature. The distance between the sample and the electrode that collected emitted electrons was about 2 cm, and a voltage of 50 V was applied between the sample and the electrode. The measurements were carried out in the spectral range between 3.5 and 6.5 eV with a 0.05 eV step. The ionization energy was determined as the threshold energy in the photoelectron emission yield spectral dependence.

Results and Discussion

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Effect of Sb2S3 Deposition Temperature

Heeding our thermal analysis study, (33) a solution of TU/SbEX 3.0 is deposited onto glass/FTO/TiO2 substrates, at 200 °C, the point after the first decomposition step, 230 °C, the point before the second decomposition step, and 260 °C, the point after the second decomposition step of SbEX.
The surface of the heat-treated Sb2S3 absorber grown at 200 °C is continuous (Figure 1a,d), composed of 100–300 nm wide and 40–90 nm thick slanted grains. The Sb2S3 absorber grown at 230 °C is 70–190 nm thick, with 150–300 nm wide grains showing signs of dewetting (Figure 1b,e), crystallizing at the expense of the surrounding material. The surface of the absorber grown at 260 °C consists of partially merged 200–1000 nm wide and 350 nm thick domes (Figure 1c,f). Notably, the catenoids and menisci connecting dewetted grains (Figure S1a,b) hint at liquid-phase interactions and capillary action during deposition and crystallization. Dewetting intensifies at a deposition temperature beyond 200 °C possibly because the transient liquid thiourea phase, which prevents oxidation and facilitates coalescence of amorphous Sb2S3 at 200 °C, decomposes faster. (15,25) Dewetting has also been observed in Sb2S3 layers grown by spray pyrolysis at 250 °C from a solution of TU/SbCl3. (34)

Figure 1

Figure 1. Top-down and cross-sectional SEM images of heat-treated Sb2S3 absorbers (in yellow) grown onto an FTO (in cyan)/TiO2 (in dark blue) substrate at deposition temperatures of (a, d) 200 °C, (b, e) 230 °C, and (c, f) 260 °C.

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According to XRD (Figure 2a), the signal can be attributed only to crystalline orthorhombic Sb2S3, and the glass/FTO/TiO2 substrate is detected in the heat-treated samples. Experimentally, an increase in Scherrer (120) crystallite size from 43 ± 6 to 55 ± 3 and 60 ± 3 nm for the 200, 230, and 260 °C samples is observed, respectively, indicating that the absorber grown at a higher deposition temperature crystallizes further. Raman spectra of the heat-treated films (Figure 2b) yield vibrational bands centered at 128, 156, 191, 239, 283, 304, and 313 cm–1, matching crystalline Sb2S3. (5)

Figure 2

Figure 2. (a) XRD patterns, (b) Raman spectra, and (c) absorption spectra of heat-treated Sb2S3 absorbers grown at 200, 230, and 260 °C, TU/SbEX 3.0. (d) X-ray photoelectron spectroscopy (XPS) survey spectrum, XPS results of (e) C 1s region, (f) Sb 3d and O 1s regions, and (g) S 2p and Sb 4s regions, and (h) valence band (VB) onset of the heat-treated Sb2S3 absorber grown at 200 °C.

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Increasing the deposition temperature of Sb2S3 from 200 to 230 and 260 °C causes a red shift in visible light absorption and a general increase in absorption (Figure 2c). Transmittance, however, increases at the same time in the 350–500 nm range (Figure S2a). The 200 °C Sb2S3 film reflects 40% of visible light and shows thin-film interference (Figure S2b), whereas the films grown at 230 and 260 °C reflect 30% without interference. The band gaps of the 200, 230, and 260 °C Sb2S3 absorbers are 1.77, 1.67, and 1.66 eV from (αhν)2 vs photon energy curves (Figure S2c) or 1.80, 1.72, and 1.71 eV via sigmoidal fits of absorption, respectively. We ascribe the decrease in band gap to the increase in Sb2S3 crystallite size representing more complete crystallization due to less carbonaceous precursor decomposition residue remaining in the film, based on the thermal analysis of SbEX. (33)
The XPS survey spectrum shows peaks of Sb, S, O, C, and N at the surface of the Sb2S3 film grown at 200 °C (Figure 2d). High-resolution XPS spectra are collected in the regions of C 1s (Figure 2e), S 2p and Sb 4s (Figure 2f), and Sb 3d and O 1s (Figure 2g).
The C 1s region presented in Figure 2e consists primarily of peaks attributed to C–C/C–H bonding, with a lesser contribution of C–O and O–C═O bonding, ascribed to exposure to hydrocarbons and CO2 in ambient air. The primary doublet signal present in Sb 3d spectra (Figure 2f) originates from the high binding energy (BE) of native oxide species (Sb2O3) (green), (16,35−37) while the low-BE shoulder (purple) is attributed to the expected lattice Sb2S3. The significant intensity of the oxide component observed here suggests a plausible sulfur deficiency during the film deposition process. Although from these surface-sensitive XPS results it is not clear how much of the oxidation is induced by the deposition itself, is manifested in the bulk film, or is due to atmospheric exposure of the surface postdeposition as observed in CSS-grown Sb2Se3 films. (38) It should be noted that the O 1s core level overlaps the Sb 3d5/2 peak position, for which two species are identified: O–Sb (Sb2O3) and adventitious oxygen weakly adsorbed on the surface.
Figure 2g shows the XPS spectra obtained in the S 2p core level region, which incorporates Sb 4s because of their close binding energy proximity (fitting results are given in Table S2). The most intense signal is attributed to S–Sb (Sb2S3) (blue) with a 2p3/2 and 2p1/2 doublet separation of 1.2 eV, which is well established. (16,39) An additional doublet species shifted to a higher BE is identified here as elemental S (purple, Figure 2f). This four-peak, two-species signal is present elsewhere in CSS-grown Sb2S3 (14) with a S–Sb–elemental S separation of 2.3 eV, however, the interpretation from Guo et al. appears to misidentify 2p3/2 and 2p1/2 components, with no mention of the origins of these two species. In the case of Sb2Se3 it has been claimed based on XPS data that elemental Se remains on the surface after Sb2Se3 oxidation to Sb2O3. (35,37)
Finally, the valence band onset is measured as 0.74 eV below the Fermi level via linear extrapolation to the low-binding-energy minima (Figure 2h). Assuming the 1.75 eV (see Figure S2a,b) extracted optical band gap to be (i) the same as the electrical band gap and (ii) correct, this indicates that EF is below the middle of the band gap, implying that the material possesses p-type conductivity. While we acknowledge surface band bending must be considered which will affect the valence band maximum (VBM) EF, a recent study on p-type Sb2Se3 demonstrated that due to downward band bending at the surface, the bulk actually showed an enhanced p-type conductivity. (40) In addition, Figure 2h shows a secondary onset at ∼2 eV that we propose is caused by the heavy film oxidation demonstrated in the core-level spectra. This is further evidenced by the presence of oxide-induced tail states which soften the VB onset, shown to disappear upon cleaving of an oxidized Sb2Se3 crystal surface. (37)
According to XRF data, the S/Sb atomic ratios are 1.25, 1.33, and 1.29 for the heat-treated Sb2S3 absorbers grown at 200, 230, and 260 °C, respectively, indicating a sulfur-deficient bulk composition likely resulting from partial oxidation (Figure 2f,g) that possibly elevates the concentration of e.g. SbS and VS point defects. (41) The average film thicknesses are 56, 129, and 205 nm (ρ = 4.6 g cm–3) for the heat-treated Sb2S3 absorbers grown at 200, 230, and 260 °C, respectively, as calculated from the Sb Lα XRF signal. The linear increase in film thickness by 2.5 nm per 1 °C of rise in deposition temperature signals that the yield of Sb2S3 increases with temperature, possibly due to a higher decomposition yield of SbEX into insoluble Sb2S3.
Dark and illuminated current–voltage (I–V) scans of the best devices based on Sb2S3 absorbers grown at 200, 230, and 260 °C are presented for reference (Figure 3a); statistics are shown in Figure 3b–g, and numeric data are shown in Table 1. As the deposition temperature is increased from 200 to 230 and 260 °C, the average JSC decreases from 12.5 to 9.2 and 8.5 mA cm–2, respectively (Figure 3b). VOC is 470–500 mV regardless of the deposition temperature (Figure 3c). Efficiency follows JSC, decreasing from 2.5 to 1.7 and 1.6% as the deposition temperature is increased from 200 to 230 and 260 °C, respectively (Figure 3d). As the deposition temperature is increased by 60 °C (Figure 3e), the slight drop in fill factor from 41 to 38% is attributed to an increase in RS (Figure 3f), because RSH is constant (Figure 3g). As the deposition temperature is increased, RS increases from 2.6 to 3.3 and 4.2 Ω cm2. The increase in RS and the decrease in current density, as the deposition temperature is increased, are attributed to the redistribution of the absorber material into clusters of up to 4 times thicker more resistive separate grains (Figure 1a–f) and the formation of a parallel junction between TiO2 and P3HT that does not generate photocurrent. The (EQE·hν)2-derived band gap (Figure S2d) correlates with the optical band gap (Figure S2c).

Figure 3

Figure 3. (a) J–V curves of the best devices. Statistics on (b) JSC, (c) VOC, (d) efficiency, (e) fill factor, (f) RS, and (g) RSH of solar cells measured in the dark or under AM1.5G conditions as a function of Sb2S3 deposition temperature.

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Table 1. Solar Cell Output Characteristics as a Function of the Sb2S3 Deposition Temperature
Sb2S3 deposition temperature, °CVOC, mVJSC, mA cm–2FF, %η, %RS, Ω cm2RSH, kΩ cm2
20049212.9422.62.00.49
 479 ± 11a12.5 ± 0.441 ± 12.5 ± 0.12.6 ± 0.30.43 ± 0.05
       
23048610.1391.93.70.22
 470 ± 219.2 ± 0.739 ± 21.7 ± 0.23.3 ± 0.60.23 ± 0.03
       
2605069.0381.74.11.2
 499 ± 108.5 ± 0.538 ± 21.6 ± 0.14.2 ± 1.10.57 ± 0.37
a

Average and standard deviation.

The coevolution of the average light absorption, JSC, XRF-derived film thickness, and RS (Figure S3) was analyzed by Pearson cross-correlation. As the absorber thicknesses for the 230 and 260 °C devices (see Figure 1e,f) exceed the charge carrier diffusion length of 200 nm reported for Sb2S3, (42) the loss in photocurrent is likely related to increased bulk recombination.
Spraying a thicker Sb2S3 film to increase JSC is not quite straightforward, as JSC (Figure S4a) and efficiency (Figure S4b) saturate after 20 min of deposition time, whereas VOC (Figure S4c) slightly increases while the fill factor (Figure S4d) decreases. The film deposited for 10 min transmits blue light after heat treatment (Figure S5a), and the TiO2 signal appears in the Raman spectrum at 145 cm–1 (Figure S5b). Therefore, the film is thin and discontinuous. Transmittance decreases and its edge red shifts in the films grown for longer times, indicating an increase in optical thickness despite a consistent band gap (Figure S5c). The JSC saturation is attributed to the high surface activity of the freshly sprayed TiO2 substrate that repeatably facilitates crystallization of Sb2S3 as up to 50 μm wide, thick pyramidal silvery grains (Figure S6a–d) during deposition that deliver less JSC than the thinner flat-plate-shaped grains obtained via heat treatment (Figure S6e–h). TiO2 surface modification will likely allow increasing the absorber thickness by suppressing the pyramidal crystallization, as we have observed in some preliminary tests.
The recombination behavior of the solar cells is investigated via I–V–T measurements under halogen lamp illumination (Figure 4a,b) and in the dark (Figure 4c,d). The deposition temperature of the absorber layer affects the second diode, seen at >0.4 V forward bias. The dominant recombination modes, calculated by extrapolating VOC to 0 K, (43) are 1.04 and 0.916 V (Figure 5a) for the 200 and 260 °C devices, respectively. Therefore, interface recombination dominates in these solar cells, apparently increasing when the absorber is grown at a higher temperature, meaning that the absorber interfaces deteriorate. Curiously, temperature-dependent VOC of fully inorganic Sb2S3 solar cells has only ever been reported down to 210 and 140 K, with a built-in voltage of 1.08 or 0.97 V. (44,45) However, whenever tunneling is present the ideality factor becomes temperature dependent, turning VOC vs T nonlinear. (46) Therefore, the activation energy calculated by extrapolating VOC might be inaccurate and should be supplemented with ΦB calculated from n and J0. Such an approach is especially useful if the I–V temperature dependence is available over a limited range. As the temperature is decreased from 320 K, efficiency peaks at 2.2% and 0.77% at 310 K for the 200 and 260 °C Sb2S3 devices, respectively (Figure 5a), whereas below 210 K device I–V behavior changes from diode to resistor. Below 310 K, efficiency, JSC, and fill factor decrease linearly in the range of 270–210 K for both cells (Figure 5a,b). The transition to resistor at 210 K marks short-circuiting or a sudden decrease in capacitance, possibly caused by delamination owing to incompatible lattice parameters at interfaces or undesirable phase transitions in one or more of the component layers.

Figure 4

Figure 4. Temperature dependent (a, c) illuminated and (b, d) dark I–V curves of solar cells based on Sb2S3 grown at (a, b) 200 and (c, d) 260 °C.

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Figure 5

Figure 5. Temperature dependence of (a) VOC, JSC, (b) fill factor and efficiency, (c) series resistance, (d) shunt resistance, and (e) ideality factor corrected saturation current of solar cells based on Sb2S3 grown at (a, b) 200 and (d, e) 260 °C. Numerical data are given in Tables S3–S6.

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The series resistance of both devices under illumination and in the dark (see Figure 5c) is fitted with a simple exponential dependence (46)
RS(T)=RS0/(1+βexp(−Ea/kT))
(1)
where RS is the series resistance, RS0 a temperature-independent series resistance, β a prefactor, Ea the activation energy, k Boltzmann’s constant, and T temperature.
The activation energy is 230 ± 46 meV in the dark and 437 ± 26 meV under illumination for the 200 °C Sb2S3 cell, which could be caused by the carriers becoming trapped at the interface, leading to a band offset. This activation energy is often attributed to the back contact barrier height. Notably, after initially increasing, RS in the dark decreases at temperatures below 260 K, hinting at a behavior more complex than can be explained by this model. The activation energy is a more consistent 274 ± 16 meV in the dark and 248 ± 10 meV under illumination for the 260 °C Sb2S3 cell, implying a rather light-insensitive behavior.
In the dark (Figure 5d), RSH of the 200 °C Sb2S3 device decreases from 108 Ω cm2 at 300 K to 104 Ω cm2 at 260 K. RSH under illumination decreases linearly from 320 to 260 K and then increases. RSH of the 260 °C Sb2S3 device increases in the dark at a constant linear slope as the temperature is decreased and follows a bowl-shaped curve under illumination. As RSH jumps in the transition zone of 270–260 K in both devices in the dark and under illumination, a thermally activated phase transition process must occur. This sudden change is a priori attributed to the phase transition of P3HT known to occur near 263 K. (47) The observed anomaly is possibly related to the nonlinear temperature dependence of the dielectric permittivity of Sb2S3 near 270 K. (48) The overall behavior of the shunt resistance is dominated by the synthesis history of the absorber layer notwithstanding.
Further information can be extracted from the temperature dependence of the saturation current density J0 (49)
nlnJ0=nlnJ00−ΦBkT
(2)
where J00 is a weakly temperature dependent prefactor and ΦB the activation energy of the saturation current. The slope of the plot of n ln J0 vs 1/kT is expected to correspond to that of ΦB (Figure 5e). The calculated activation energy values are 1.75 ± 0.02 eV in the dark and 1.65 ± 0.06 eV under illumination for the 200 °C device, close to the Sb2S3 band gap of 1.75 eV. The 0.1 eV smaller activation energy under illumination reveals that interface recombination is the dominant mechanism, which is ascribed to Fermi level pinning or narrowing of the band gap at the interface. (46) For the 260 °C Sb2S3 device, the activation energy is 1.18 ± 0.11 eV at the “high” temperature, 1.55 ± 0.02 eV at the “low” temperature in the dark, and 1.84 ± 0.09 eV under illumination (Figure 5e). As ΦB > Eg, bulk recombination within the absorber is likely in balance with or dominates interface recombination. Notably, ΦB calculated from the temperature dependence of n and J0 is larger than when VOC is extrapolated for both devices. These Sb2S3 solar cells operate efficiently at −53 to +47 °C, corresponding to the temperate, arid, and continental climate zones, (50) which account for some of the most densely populated areas on Earth, whereas performance is apparently limited by interface and tunneling recombination.
Deep level transient spectroscopy (DLTS) analysis is conducted on the two devices with deposition temperatures of 200 and 260 °C, the least similar under J–V analysis. After initial DLTS testing, it is found that sweeping the main junction field, the typical approach for PV device measurement, (32,51) produces capacitance transients with a poor signal-to-noise ratio, making extraction of defect properties impossible. An alternative approach is to take advantage of the device’s back contact field to produce a bias sweep. This is found to produce significantly higher quality capacitance transients, with Figure 6a showing extracted ΔC values as a function of temperature for a 48 ms period width measurement. Capacitance values are normalized to allow a simple and direct comparison of the two sample spectra. Defect levels are observed as peaks in the ΔC spectra, where the emission rate of the defect state is maximized within the parameters of the particular measurement setup (i.e., changing the period width or effective rate window will shift the peak position). By tracking the peak positions observed for a range of correlator functions applied to the recorded capacitance transients, an Arrhenius assessment can be constructed (Figure 6b), with the energetic position of trap levels, ET, and associated capture cross sections, σp, being extracted (Table 2). Because the absorber material is p-type, ET values are measured with respect to the valence band maxima. Using the extracted values, the equivalent spectra modeled for those trap states are overlaid on the DLTS spectra in Figure 6a. In both samples, three distinct defect levels are observed but with a shift in prominence of the levels between the two temperatures. For the 200 °C sample, a deeper level at 345 meV is dominant, while for the 260 °C sample, a shallower 123 meV level is more pronounced. A level of 284 meV is effectively invariant between the two samples. The presence of a more dominant deep level in the 200 °C sample would be anticipated to increase recombination, lower carrier lifetime, and reduce device VOC. This agrees well with the I–V data for these samples where, despite the overall device performance being lower, the 260 °C sample shows an improved VOC, which we may infer is due to the reduced presence of the 345 meV deep defect level. While the source of these defect levels cannot be interrogated directly via DLTS, instead reference to density functional theory (DFT) calculations of defect formation energies can offer some insight. Defect formation energy calculations for Sb2S3 show a triplet of defect levels in an energy range similar to those observed here which are caused by the various charge states of the antimony vacancy (VSb) defect. (14) Hence, what we may infer from this is that the change in deposition temperature has likely caused a modification of the VSb content between the two absorbers, necessitating further study on the topic.

Figure 6

Figure 6. Deep level transient spectroscopy (DLTS) analysis for Sb2S3 solar cells with absorber layers deposited at 200 and 260 °C showing (a) normalized ΔC values extracted from capacitance transients as a function of temperature and (b) Arrhenius determination of trap energy and capture cross section with values given in Table 2. Determined values were then used to model spectra overlaid on measurement data in Figure 6a.

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Table 2. Defect Level Energies (ET) and Capture Cross Section (σp) Values Extracted from DLTS Analysis
defect levelET, meVσp, cm–2
level A123 ± 3(1.10 ± 0.28) × 10–19
level B284 ± 4(2.24 ± 0.61) × 10–16
level C345 ± 8(1.49 ± 0.81) × 10–17

Effect of Thiourea Concentration

Having established that 200 °C is the optimal deposition temperature for Sb2S3 with regard to absorber conformity and solar cell efficiency, the concentration of thiourea is varied from 0.5 to 6.0 TU/SbEX at constant Sb3+ concentration in the following experiments.
SEM reveals that the heat-treated Sb2S3 absorber grown from the TU/SbEX 0.5 solution is discontinuous and is at most 50 nm thick (Figure 7a,g). TU/SbEX 1.0 yields a coalesced 20–90 nm thick Sb2S3 absorber composed of grains 1 μm in size by 100–200 nm (Figure 7b, h). The grain size (70–230 nm vs 70–270 nm) and thickness (30–80 nm vs 50–100 nm) of the TU/SbEX 1.5 (Figure 7c,i) and 3.0 absorbers’ (Figure 7d,j) values are similar. The TU/SbEX 4.5 absorber is 60–120 nm thick (Figure 7e,k), and 130–380 nm wide, 1 μm long spherulites cover most of the substrate. The flat spherulitic morphology persists at TU/SbEX 6.0 (Figure 7f,l), whereas the film thickness decreases to 30–80 nm.

Figure 7

Figure 7. Top-down and cross-sectional SEM images of heat-treated Sb2S3 absorbers (in yellow) grown onto a FTO (in cyan)/TiO2 (in dark blue) substrate at a deposition temperature of 200 °C by USP from a solution with TU/SbEX molar ratios of (a, g) 0.5, (b, h) 1.0, (c, i) 1.5, (d, j) 3.0, (e, k) 4.5, and (f, l) 6.0.

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At TU/SbEX 1.0 and above, the top surface of the coalesced Sb2S3 absorber is flattened and deviates from the substrate morphology (Figure 7h–l). The flattening possibly proceeds through curvature-driven self-diffusion, (52) whereby upon heating the amorphous Sb2S3 at the tips of the FTO/TiO2 ridges flows to fill in the pits between them, becoming uneven in local thickness to the extent that the regions of the substrate with the highest aspect ratio are left bare. Consequently, TiO2/P3HT shunts inevitably form in the vicinity of the uncovered FTO/TiO2 ridges. Dewetting has to be eliminated to create a denser and pinhole free spray-Sb2S3 film either by applying interfacial seed layers (13) or TiO2 surface modification. (22)
The XRD patterns (Figure 8a) and Raman spectra (Figure 8b) of all of the heat-treated absorbers grown at 200 °C contain only crystalline Sb2S3, absent any additional bulk phases. A generalized texture coefficient is required to gauge the proportion of each crystal growth direction in the XRD patterns of Sb2S3 vs the powder reference, which is calculated as
Chkl=Ihkl/∑IhklIhkl,ref/∑Ihkl,ref
(5)
where Chkl is the texture coefficient, Ihkl the measured intensity in cps deg, and Ihkl,ref the reference intensity of each detected crystallographic growth direction corresponding to the Miller indices (hkl) of the No. 62 Pbnm system.

Figure 8

Figure 8. (a) X-ray diffraction (XRD) patterns, (b) Raman spectra, (c) cumulative XRD texture coefficients, (d) absorption spectra, X-ray photoelectron spectroscopy (XPS) results of (e) S 2p region and (f) intensity contributions, extrapolated to TU/SbEX 0, and XPS results of (g) Sb 3d and (h) Sb 4d region, and (i) intensity contributions, extrapolated to TU/SbEX 0, of heat-treated Sb2S3 absorbers grown onto glass/FTO/TiO2 from a solution with variable molar ratios of TU/SbEX.

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The TU/SbEX 0.5–1.0 samples are outliers in terms of the texture coefficient because of the small number and intensity of Sb2S3 peaks (Figure 8b), whereas the trend is consistent thereafter. The (110) and (041) texture coefficients dominate in the TU/SbEX 1.5 sample. At TU/SbEX 3.0 the (110) peak disappears. The relative proportion of only the (020), (120), (130), (230), and (041) texture coefficients increases. Next, at TU/SbEX 4.5 the (220) peak disappears. Consequently, the proportion of the (020) and (041) texture coefficients is maximized, diminishing that of the (120), (230), (121), and (221) texture coefficients. At TU/SbEX 6.0, the (121) and (221) peaks disappear, whereas the proportion of the (120) and (141) texture coefficients increases, decreasing the proportion of the (020) and (041) texture coefficients.
Considering the sequential disappearance of the (110), (220), (121), and (221) peaks as the TU/SbEX ratio is increased, the crystal structure of the Sb2S3 films can be modified by changing the concentration of TU in the spray solution. Despite the mostly horizontal (hk0) growth directions observed in this study, some up to 6.6% efficiency Sb2S3 solar cells are based on chemically grown Sb2S3 thin films exhibiting larger than usual (020) and (120) peak intensities. (11,12) Thus, we refrain from interpreting preferential growth in the (221), (211), and other (hk1) directions as strictly mandatory to achieve high efficiency. Nonetheless, the relative proportion of the (041) and (141) texture coefficients does correlate with the increased average device efficiency presented afterward.
The absorbers grown from the TU/SbEX 0.5 and 1.0 solutions are considerably more transparent at 400 nm wavelength (22 and 6.9%) than films grown using more thiourea in the solution (<3%) (Figure S7a). The TU/SbEX 0.5 and 1.0 based absorbers are thus considered to be thin and discontinuous and the remainder conformal.
After heat treatment, the Sb2S3 films develop an average reflectance of 33–45% in the 350–750 nm wavelength range (Figure S7b). Such high reflectance could facilitate trapping light between a partially transparent absorber and a back reflector, e.g., Au, Ag, and Ni, in nontransparent cells. A highly reflective absorber is not a concern if it absorbs all incident light, yet is nonetheless detrimental for semitransparent and bifacial solar cells─a primary application for Sb2S3 solar cells, because current density is limited by the reduction in absorbed light. Hence, an antireflective absorber or surface texturization at the Sb2S3/HTL interface is recommended in semitransparent devices to maximize current density.
The band gap of the heat-treated Sb2S3 absorbers is 1.76–1.88 eV from the optical spectra (Figure S7c). As the ratio of TU/SbEX in solution is increased from 0.5 to 1.0, 1.5, 3.0, 4.5, and 6.0, the average absorption in the 350–750 nm wavelength range evolves from 27 to 31, 35, 35, 41, and 38% (Figure 8d), respectively. Observably, more thiourea in the solution yields an absorber with an increased optical thickness until TU/SbEX 4.5. The Sb2S3 yield increases probably because the surface is less exposed to air during each deposition cycle, improving adhesion between the amorphous Sb2S3 sublayers.
To prove this claim, we recorded XPS spectra of Sb2S3 films grown from different TU/SbEX molar ratios. After calibrating for charging offset via auspicious carbon (284.5 eV), S 2p, Sb 4s, Sb 3d, and Sb 4d peak positions (Tables S7–S9) and widths are close to literature values. (6,31)
In the TU/SbEX 0.5 sample, in the S 2p region, doublets attributed to S–S or elementary S, S–Sb (S2–), and S–O (SO42–) are observed (Figure 8e). Thus, the explanation provided in the previous section is likely oversimplified for these Sb2S3 films due to the various organosulfur compounds observed at ∼168 eV (Figure 8e). Evidently, the concentration of TU is too low to prevent extensive surface oxidation of Sb2S3 into Sb2O3 and likely formation of polysulfates (7) of the (Sb2O3)m·(SO3)n type. Without a protective agent such as TU, Sb2O3 is always obtained at a deposition temperature near 200 °C. (25) In the TU/SbEX 1.0 sample, the proportion of the sulfate peaks has diminished, and the proportion of S0 peaks has increased with respect to the S2– peak intensity (Figure 8f). It is reasonable to conclude that doubling the TU concentration from 0.5 to 1.0 protects the surface against oxidation, yielding Sb sulfates on the surface, an intermediary elementary sulfur layer, and an unoxidized Sb2S3 bulk. Increasing the TU/SbEX molar ratio to 3.0 further suppresses oxidation, as the relative intensity of sulfate and elementary sulfur peaks is drastically decreased.
The Sb 3d region resembles the S 2p range, whereby the Sb–O doublet peaks dominate at TU/SbEX 0.5 and 1.0, and shoulder peaks of Sb–S are present only in the TU/SbEX 3.0 sample (Figure 8g). The difference in the proportion of Sb–S and Sb–O intensities in the Sb 3d region of samples grown in different batches (Figure 2g vs Figure 8g) is primarily attributed to locally varying oxidation (Figure S8). In addition, XPS spectra of the Sb 4d region are presented because there is no overlap with characteristic lines of other elements, as opposed to the unavoidable overlap of the Sb 3d5/2 and O 1s peaks that leads to uncertainty in data interpretation. The trend of reduced oxidation of Sb2S3 as a result of increased TU concentration is also observed in the Sb 4d region (Figure 8h) with the relative proportion of Sb–S being twice as large vs the Sb 3d region (Figure 8i).
The S/Sb atomic ratios from XRF data are 1.07, 1.53, 1.54, and 1.52 for the heat-treated Sb2S3 absorbers grown from solutions of TU/SbEX of 0.5, 1.5, 4.5, and 6.0, respectively. The sulfur-poor composition at TU/SbEX 0.5 is caused by partial oxidation during deposition, as proven by XPS, whereas the remaining samples have a nearly stoichiometric composition. Therefore, based on XPS and XRF, it is safe to assume that TU/SbEX in excess of 3.0 is required to grow thoroughly phase pure unoxidized Sb2S3 absorbers by USP. In the case of TU/SbEX 0.5, 1.5, 4.5, and 6.0, average Sb2S3 film thicknesses are calculated from Sb Lα XRF data as 25, 62, 75, and 53 nm, correlating well with optical absorption, as shown later. TU/SbEX 4.5 yields the maximum Sb2S3 film growth rate of 3.8 nm min–1, whereas increasing to TU/SbEX 6.0 slows the film growth rate. We suppose that excess TU blocks some SbEX from reaching the surface of the substrate, repelling SbEX into the aerosol exhaust stream.
The I–V of the best devices (Figure 9a) correlates with absorption, film thickness, and EQE (Figure 9b and Figure S9) because of JSC, as the TU/SbEX 0.5 device is the worst and the 4.5 device is the best. Overall EQE intensity and response in red light are enhanced as TU/SbEX is increased, attributed to increased absorber thickness, culminating in a maximum integral EQE area at TU/SbEX 4.5, whereas the decrease at 6.0 is linked to a thinner absorber. The band gap of the heat-treated Sb2S3 absorbers is calculated to be 1.76–1.79 eV from the (EQE·hν)2 spectra (Figure S10), in agreement with optical measurement results. In addition, JSC of the best cells measured by I–V (Figure 9a) is close to JSC integrated from EQE spectra (Figure 9b and Table 3), exceeding it by 0.2–0.9 mA cm–2. The offset in JSC is attributed to the shape of the light spectrum emitted by the LED and the Xe light source, the vastly different illumination intensity used with these methods, and the photoactivated shunting (26) in Sb2S3 devices.

Figure 9

Figure 9. (a) J–V curves and (b) EQE and integrated JSC of best devices based on Sb2S3 films grown with a variable molar ratio of TU/SbEX. (c) SEM cross-section of the best device. ( Statistics on (d) JSC, (e) VOC, (f) efficiency, (g) fill factor, (h) series resistance, and (i) shunt resistance. Band diagram of the solar cell layer structure at (j) TU/SbEX 3.0 and (k) 4.5.

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Table 3. Solar Cell Output Characteristics as a Function of the TU/SbEX Molar Ratio in Spray Solution
  JSC, mA cm–2    
TU/SbEXVOC, mVI–VEQEFF, %η, %RS, Ω cm2RSH, kΩ cm2
0.55679.58.6492.61.22.6
 555 ± 22a8.2 ± 0.8 48 ± 22.2 ± 0.31.7 ± 0.21.4 ± 0.8
        
1.057411.710.8483.21.81.2
 559 ± 4610.9 ± 0.4 47 ± 42.9 ± 0.52.0 ± 0.21.9 ± 1.0
        
1.554313.412.5513.73.21.5
 534 ± 711.8 ± 0.8 52 ± 13.3 ± 0.32.7 ± 0.42.4 ± 0.9
        
3.054412.912.7513.62.91.1
 535 ± 1312.2 ± 0.5 51 ± 13.3 ± 0.22.7 ± 0.40.9 ± 0.1
        
4.555614.714.1504.13.01.2
 544 ± 1513.5 ± 0.7 49 ± 23.6 ± 0.32.9 ± 0.41.5 ± 0.6
        
6.055613.413.1523.92.60.9
 529 ± 3612.2 ± 0.8 49 ± 53.2 ± 0.62.3 ± 0.30.9 ± 0.3
a

Average and standard deviation.

The cross-section of the best TU/SbEX 4.5 Sb2S3 solar cell (Figure 9c) illustrates the conformal coverage of TiO2 on FTO and Sb2S3 on TiO2. However, the top surface of Sb2S3 is flat likely because Sb2S3 is formed in a liquid–liquid reaction. (15) Furthermore, the surface energy mismatch with TiO2 causes dewetting of Sb2S3, (13,15) and thus poor conformality, which is detrimental to photovoltaic performance because it not only permits electrical and physical shunting between TiO2 and Au through the ∼20 nm thin P3HT layer but also reduces the uniformity of photocurrent generation.
Considering the average device parameters, increasing TU/SbEX from 0.5 to 4.5 improves the average JSC by a factor of 1.67 (Figure 9d) from 8.1 to 13.5 mA cm–2, whereas VOC (Figure 9e) is relatively unaffected (Table 3). Thus, as TU/SbEX changes from 0.5 to 1.0, 1.5, 3.0, 4.5, and 6.0, efficiency (Figure 9f), driven by JSC, evolves to 2.2, 2.9, 3.3, 3.3, 3.6, and 3.2%, respectively. The fill factor hovers at around 0.5 (Figure 9g) for all devices. The corresponding best devices attain efficiencies of 2.7, 3.2, 3.7, 3.7, 4.1, and 3.9%.
RS evolves similarly to JSC (Figure 9h). Hence, we ascribe the increase in RS primarily to an increase in absorber thickness and not TU/SbEX. RSH increases from 1.4 kΩ cm2 at TU/SbEX 0.5 to 2.4 kΩ cm2 at 1.5, thereafter decreasing to 0.9 kΩ cm2 at 6.0 (Figure 9i). RSH is likely enhanced by surface passivation that occurs at the Sb2S3/P3HT interface in the TU/SbEX 0.5–1.5 devices owing to the presence of Sb2O3, elementary sulfur, sulfates, or a combination of them (Figure 8e). Controlled surface oxidation is a well-known passivation technique to improve Sb2S3 solar cell RSH and, thereby, fill factor. (53)
To discern how TU/SbEX affects the solar cell energy levels, the energy level diagrams of the TU/SbEX 3.0 (Figure 9j) and 4.5 (Figure 9k) Sb2S3 devices are experimentally determined for every constituent semiconductor layer in the stack. The ionization energy level values are obtained from the PES spectra (Figure S11). The valence band maximum (VBM) of the TU/SbEX 3.0 Sb2S3 absorber is positioned at −4.84 eV vs vacuum energy, resulting in a 0.53 eV potential difference with the conduction band minimum (CBM) of TiO2. As a result, a favorable recombination pathway is created for photogenerated holes at the TiO2/Sb2S3 interface. At the same time, there is a 0.38 eV offset in the VBM of P3HT and Au, creating an undesired back contact barrier. Furthermore, the offset between the CBM of TiO2 and the CBM of Sb2S3 is 1.22 eV, which is considered suboptimal for electron extraction. Increasing TU/SbEX to 4.5 causes multiple changes. The VBM and CBM of the Sb2S3 absorber respectively downshift to −5.05 and −3.31 eV (Figure 9k), respectively. Therefore, the TiO2 CBM and Sb2S3 CBM offsets are reduced to 1.00 eV, enhancing electron extraction efficiency. The TiO2 CBM and Sb2S3 VBM offset increases to 0.74 eV, resulting in a net 0.21 eV improvement in blocking hole recombination at the TiO2/Sb2S3 interface. Moreover, the VBM of P3HT is downshifted to −4.79 eV, possibly due to the downshift of the CBM and VBM of the underlying Sb2S3 layer. Thereby, the P3HT/Au back contact barrier is reduced to 0.21 eV, which is unlikely to form a severe back contact barrier. The downshift in the VBM of Sb2S3 at TU/SbEX 4.5 vs 3.0 is ascribed to increased Sb2S3 phase purity at the Sb2S3/P3HT interface because of suppressed oxidation during deposition.

Conclusions

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Increasing the deposition temperature of Sb2S3 above 200 °C yielded a thicker and bulk-phase-pure yet discontinuous absorber due to dewetting during the liquid-phase decomposition of SbEX to Sb2S3. The deteriorated morphology of the absorber promoted shunting and decreased short-circuit current density in solar cells. According to temperature-dependent current–voltage analysis, the solar cell based on the Sb2S3 absorber grown at 200 °C was mainly limited by interface and tunneling related recombination, whereas the 260 °C device was affected by bulk recombination, as well. Further analysis by DLTS revealed that increasing the deposition temperature affected the concentration of VSb, resulting in increased open-circuit voltage in the device based on Sb2S3 grown at 260 °C. Increasing the molar ratio of thiourea to SbEX increased the Sb2S3 film growth rate by suppressing bulk and surface oxidation and decreasing the number and proportion of crystal growth directions lying horizontally on the substrate. Thereby, the formation of a continuous and flat absorber film was promoted, yielding proportionally higher short-circuit current density as the thickness, bulk, and surface purity of the absorber increased. Overall, the best solar cell efficiency of 4.1% was achieved at a TU/SbEX molar ratio of 4.5 at an average absorber thickness of 75 nm. Increasing the molar ratio from 3.0 to 4.5 resulted in an ∼0.2 eV more favorable energy level alignment at both the Sb2S3/P3HT and the P3HT/Au interface. Our findings highlight the importance of developing synthesis conditions to achieve the best solar cell device performance for an Sb2S3 absorber layer pertaining to the chosen deposition method, experimental setup, and precursors.

Supporting Information

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The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.3c08547.

  • List of chemicals used, additional UV–vis and EQE spectra, UV–vis spectra, I–V statistics, and optical microscope images of the deposition time series, SEM images, tabulated I–V–T and XPS fit results, Pearson correlation graphs, 2D XPS data, and PES fit curves for the partial solar cell stacks (PDF)

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Author Information

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  • Corresponding Authors
    • Jako S. Eensalu - Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia;  Max IV Laboratory, Lund University, Fotongatan 2, Lund 224 84, Sweden;  Orcidhttps://orcid.org/0000-0002-4312-0227;  Email: [email protected]
    • Malle Krunks - Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia;  Email: [email protected]
  • Authors
    • Sreekanth Mandati - Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia;  Orcidhttps://orcid.org/0000-0002-3317-271X
    • Christopher H. Don - Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
    • Harry Finch - Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
    • Vinod R. Dhanak - Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
    • Jonathan D. Major - Department of Physics/Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 3BX, United Kingdom
    • Raitis Grzibovskis - Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga LV-1063, Latvia
    • Aile Tamm - Laboratory of Thin Film Technology, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia;  Orcidhttps://orcid.org/0000-0002-0547-0824
    • Peeter Ritslaid - Laboratory of Thin Film Technology, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia;  Orcidhttps://orcid.org/0000-0002-3603-2237
    • Raavo Josepson - Division of Physics, Department of Cybernetics, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
    • Tanel Käämbre - Max IV Laboratory, Lund University, Fotongatan 2, Lund 224 84, Sweden;  Laboratory of X-Ray Spectroscopy, Institute of Physics, Tartu University, W. Ostwaldi Str. 1 50411 Tartu, Estonia
    • Aivars Vembris - Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga LV-1063, Latvia
    • Nicolae Spalatu - Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia;  Orcidhttps://orcid.org/0000-0003-0234-2170
    • Ilona Oja Acik - Laboratory of Thin Film Chemical Technologies, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
  • Author Contributions

    The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.

  • Notes
    The authors declare no competing financial interest.

Acknowledgments

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J.S.E. thanks Beamline Specialist Dr. Weimin Wang for instructing how to operate the solid-state endstation at the FinEstBeAMS beamline at Max IV Lab. The authors also thank the two anonymous reviewers for their contribution. This reearch was funded by the Estonian Research Council project PRG627, the Estonian State Shared Service Center project AR20015, the Estonian Research Council project TT20 “(MAX-TEENUS)”, the Archimedes Foundation project AR17092 “(NAMUR+)”, the Center of Excellence project TAR16016EK, and the European Commission project VFP20035 5GSOLAR-952509. Funding for the work was provided by the EPSRC via EP/N014057/1 and EP/W03445X/1. The present work was financially supported by the Estonian Research Council (PRG4), and this research was also supported by the EU through the European Regional Development Fund Center of Excellence project TK134- “Emerging orders in quantum and nanomaterials”. The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016- 2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. Financial support was also provided by the European Regional Development Fund (grant No. MAX-TEENUS 2014-2020.4.01.20-0278 to University of Tartu). We acknowledge MAX IV Laboratory for offline and beam time on the SSES branch of Beamline FinEstBeAMS as part of in-house research. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council under contract 2018-07152, the Swedish Governmental Agency for Innovation Systems under contract 2018-04969, and Formas under contract 2019-02496.

Abbreviations

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α

absorption coefficient

CBM

conduction band minimum

DFT

density functional theory

DLTS

deep level transient spectroscopy

EQE

external quantum efficiency

FF

fill factor

FTO

fluorine-doped tin oxide

η

power conversion efficiency

HTL

hole transport layer

JSC

short-circuit current density

PES

photoelectron emission spectroscopy

PV

photovoltaic

P3HT

poly(3-hexylthiophene-2,5-diyl)

RS

series resistance

RSH

shunt resistance

SbS

sulfur antimony antisite

SEM

scanning electron microscope

TU/SbEX

thiourea to antimony ethyl xanthate molar ratio

VBM

valence band maximum

VOC

open-circuit voltage

VSb

antimony vacancy

VS

sulfur vacancy

XPS

X-ray photoelectron spectroscopy

XRD

X-ray diffraction

XRF

X-ray fluorescence

References

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This article references 53 other publications.

  1. 1
    Solar Energy; Richter, C., Lincot, D., Gueymard, C. A., Eds.; Springer: 2012; pp 170– 173.
    Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Greenwood, N. N.; Earnshaw, A. Arsenic, Antimony and Bismuth. In Chemistry of the Elements, 2nd ed.; Butterworth-Heinemann: 1997; pp 581– 582.
    Google Scholar
    There is no corresponding record for this reference.
  3. 3
    U.S. Geological Survey. Mineral Commodity Summaries 2022; U.S. Geological Survey: 2022; p 202.  DOI: 10.3133/mcs2022 .
    Google Scholar
    There is no corresponding record for this reference.
  4. 4
    Dong, J.; Liu, Y.; Wang, Z.; Zhang, Y. Boosting VOC of Antimony Chalcogenide Solar Cells: A Review on Interfaces and Defects. Nano Select 2021, 2 (10), 1818– 1848,  DOI: 10.1002/nano.202000288
    Google Scholar
    4
    Boosting VOC of antimony chalcogenide solar cells: A review on interfaces and defects
    Dong, Jiabin; Liu, Yue; Wang, Zuoyun; Zhang, Yi
    Nano Select (2021), 2 (10), 1818-1848CODEN: NSAECD; ISSN:2688-4011. (Wiley-VCH Verlag GmbH & Co. KGaA)
    A review. Antimony chalcogenides, including Sb2S3, Sb2Se3, and Sb2(S, Se)3, have been developed as attractive non-toxic and earth-abundant solar absorber candidates among the thin-film photovoltaic devices. Presently, a record certified power conversion efficiency of 10.5% has been demonstrated for antimony chalcogenide solar cells, which is significantly lower than that of Cu2(In, Ga)Se2 (23.35%) and CdTe (22.1%) thin-film solar cells. The inferior performance in antimony chalcogenide solar cells is mainly owing to a large open-circuit voltage (VOC) deficit resulted from the defect and interface-assisted recombination. Herein, a comprehensive review on the recent advancements interface band alignment and defect passivation are carried out. This review will provide a solid understanding on the interfaces and defects of antimony chalcogenide solar cells, which is beneficial to the research and development of such kind of solar cells.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xlt1Onur0%253D&md5=3dbd9dd928045a428497c33711e907d2
  5. 5
    Gutiérrez, Y.; Ovvyan, A. P.; Santos, G.; Juan, D.; Rosales, S. A.; Junquera, J.; García-Fernández, P.; Dicorato, S.; Giangregorio, M. M.; Dilonardo, E.; Palumbo, F.; Modreanu, M.; Resl, J.; Ishchenko, O.; Garry, G.; Jonuzi, T.; Georghe, M.; Cobianu, C.; Hingerl, K.; Cobet, C.; Moreno, F.; Pernice, W. H. P.; Losurdo, M. Interlaboratory Study on Sb2S3 Interplay between Structure, Dielectric Function, and Amorphous-to-Crystalline Phase Change for Photonics. iScience 2022, 25 (6), 104377,  DOI: 10.1016/j.isci.2022.104377
    Google Scholar
    5
    Interlaboratory study on Sb2S3 interplay between structure, dielectric function, and amorphous-to-crystalline phase change for photonics
    Gutierrez, Yael; Ovvyan, Anna P.; Santos, Gonzalo; Juan, Dilson; Rosales, Saul A.; Junquera, Javier; Garcia-Fernandez, Pablo; Dicorato, Stefano; Giangregorio, Maria M.; Dilonardo, Elena; Palumbo, Fabio; Modreanu, Mircea; Resl, Josef; Ishchenko, Olga; Garry, Guy; Jonuzi, Tigers; Georghe, Marin; Cobianu, Cornel; Hingerl, Kurt; Cobet, Christoph; Moreno, Fernando; Pernice, Wolfram H. P.; Losurdo, Maria
    iScience (2022), 25 (6), 104377CODEN: ISCICE; ISSN:2589-0042. (Elsevier B.V.)
    Antimony sulfide, Sb2S3, is interesting as the phase-change material for applications requiring high transmission from the visible to telecom wavelengths, with its band gap tunable from 2.2 to 1.6 eV, depending on the amorphous and cryst. phase. Here we present results from an interlab. study on the interplay between the structural change and resulting optical contrast during the amorphous-to-cryst. transformation triggered both thermally and optically. By statistical anal. of Raman and ellipsometric spectroscopic data, we have identified two regimes of crystn., namely 250°C ≤ T < 300°C, resulting in Type-I spherulitic crystn. yielding an optical contrast Δn ∼ 0.4, and 300 ≤ T < 350°C, yielding Type-II crystn. bended spherulitic structure with different dielec. function and optical contrast Δn ∼ 0.2 below 1.5 eV. Based on our findings, applications of on-chip reconfigurable nanophotonic phase modulators and of a reconfigurable high-refractive-index core/phase-change shell nanoantenna are designed and proposed.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitVygtbbO&md5=9fb54aa09eab1b22e76e8efc4a3c9ae1
  6. 6
    Büttner, P.; Scheler, F.; Döhler, D.; Barr, M. K. S.; Bosch, M.; Rey, M.; Yokosawa, T.; Hinz, S.; Maultzsch, J.; Spiecker, E.; Vogel, N.; Mínguez-Bacho, I.; Bachmann, J. Continuous, Crystalline Sb2S3 Ultrathin Light Absorber Coatings in Solar Cells Based on Photonic Concentric p-i-n Heterojunctions. Nano Energy 2022, 103, 107820  DOI: 10.1016/j.nanoen.2022.107820
    Google Scholar
    6
    Continuous, crystalline Sb2S3 ultrathin light absorber coatings in solar cells based on photonic concentric p-i-n heterojunctions
    Buettner, Pascal; Scheler, Florian; Doehler, Dirk; Barr, Maissa K. S.; Bosch, Michael; Rey, Marcel; Yokosawa, Tadahiro; Hinz, Sandra; Maultzsch, Janina; Spiecker, Erdmann; Vogel, Nicolas; Minguez-Bacho, Ignacio; Bachmann, Julien
    Nano Energy (2022), 103 (Part_B), 107820CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)
    Many modern types of solar cells that rely exclusively on earth-abundant non-toxic materials include interfaces between a heavier metal chalcogenide and another type of semiconductor. Often, the chem. (adhesion) and phys. (charge transfer) characteristics of those interfaces are the defining factors for the final device performance. Here, we describe that a ZnS adhesion layer is not sufficient to prevent the dewetting of Sb2S3 upon annealing a thin layer of it on an oxidic surface if the substrate is not planar and features highly curved surfaces. An ALD-coated sacrificial capping layer of ZnO prevents the morphol. rearrangements of Sb2S3 during thermal crystn. and can be removed subsequently. When implemented towards a photovoltaic p-i-n heterojunction, this strategy furnishes perfect conformality of the layer stack but unsatisfactory performance. The correlation of interface chem. with the elec. properties and the device performance identifies a reducing effect of ZnO at. layer deposition chem. on the Sb2S3 surface as the cause of Zn diffusion into the light absorbing semiconductor. This deleterious doping can be prevented by a preliminary oxidative treatment of the Sb2S3 surface with ozone. When applied to a structured substrate consisting of ordered arrays of nanospheres, this approach yields the first ever concentric p-i-n heterojunction solar cells with photonic light trapping effect-a geometry which in comparison with std. scattering layers on top inherently generates a very large refractive index contrast. In the red part of the visible spectrum, light absorption amts. to the value expected with four passes through a planar layer of the thickness used here (35 nm Sb2S3). This effect allows us to demonstrate > 5% overall solar energy conversion efficiency with only 35 nm of a simple light absorber phase that uses no toxic, rare materials.
    >> More from SciFinder ®
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  7. 7
    Thorneycroft, W. E. Antimony and Sulphur. In Antimony and Bismuth; Friend, J. N., Ed.; ; Charles Griffin: 1936; A Text Book of Inorganic Chemistry, Vol. VI, Part V, pp 97– 101.
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    Kim, D.-H.; Lee, S.-J.; Park, M. S.; Kang, J.-K.; Heo, J. H.; Im, S. H.; Sung, S.-J. Highly Reproducible Planar Sb2S3-Sensitized Solar Cells Based on Atomic Layer Deposition. Nanoscale 2014, 6 (23), 14549– 14554,  DOI: 10.1039/C4NR04148H
    Google Scholar
    8
    Highly reproducible planar Sb2S3-sensitized solar cells based on atomic layer deposition
    Kim, Dae-Hwan; Lee, Sang-Ju; Park, Mi Sun; Kang, Jin-Kyu; Heo, Jin Hyuck; Im, Sang Hyuk; Sung, Shi-Joon
    Nanoscale (2014), 6 (23), 14549-14554CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
    A high-quality Sb2S3 thin-absorber with controllable thickness was reproducibly formed by at. layer deposition (ALD) technique. Compared with conventional chem. bath deposition (CBD), the Sb2S3 absorber deposited by ALD did not contain oxide or oxygen impurities and showed a very uniform thickness of Sb2S3 absorbers formed on a rough surface of dense blocking TiO2/F-doped SnO2 (bl-TiO2/FTO) substrate. The planar ALD-Sb2S3 solar cells comprised of Au/Poly-3-hexylthiophene/ALD-Sb2S3/bl-TiO2/FTO showed significantly improved power conversion efficiency of 5.77% at 1 sun condition and narrow efficiency deviation, whereas the planar CBD-Sb2S3 solar cells exhibited 2.17% power conversion efficiency. The high efficiency and good reproducibility of ALD-Sb2S3 solar cell devices is attributed to reduced backward recombination because of the inhibition of oxide defects within ALD-Sb2S3 absorber and the conformal deposition of very uniform Sb2S3 absorbers on the blocking TiO2 surface by ALD process.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslaqsrnE&md5=322b872b7a85370a52e8e51cb8b30528
  9. 9
    Wang, S.; Zhao, Y.; Che, B.; Li, C.; Chen, X.; Tang, R.; Gong, J.; Wang, X.; Chen, G.; Chen, T.; Li, J.; Xiao, X. A Novel Multi-Sulfur Source Collaborative Chemical Bath Deposition Technology Enables 8%-Efficiency Sb2S3 Planar Solar Cells. Adv. Mater. 2022, 34 (41), 2206242  DOI: 10.1002/adma.202206242
    Google Scholar
    9
    A Novel Multi-Sulfur Source Collaborative Chemical Bath Deposition Technology Enables 8%-Efficiency Sb2S3 Planar Solar Cells
    Wang, Shaoying; Zhao, Yuqi; Che, Bo; Li, Chuang; Chen, Xueling; Tang, Rongfeng; Gong, Junbo; Wang, Xiaomin; Chen, Guilin; Chen, Tao; Li, Jianmin; Xiao, Xudong
    Advanced Materials (Weinheim, Germany) (2022), 34 (41), 2206242CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Sb2S3 as a light-harvesting material has attracted great attention for applications in both single-junction and tandem solar cells. Such solar cell has been faced with current challenge of low power conversion efficiency (PCE), which has stagnated for 8 years. It has been recognized that the synthesis of high-quality absorber film plays a crit. role in efficiency improvement. Here, using fresh precursor materials for antimony (antimony potassium tartrate) and combined sulfur (sodium thiosulfate and thioacetamide), a unique chem. bath deposition procedure is created. Due to the complexation of sodium thiosulfate and the advantageous hydrolysis cooperation between these two sulfur sources, the heterogeneous nucleation and the S2- releasing processes are boosted. As a result, there are noticeable improvements in the deposition rate, film morphol., crystallinity, and preferred orientations. Addnl., the improved film quality efficiently lowers charge trapping capacity, suppresses carrier recombination, and prolongs carrier lifetimes, leading to significantly improved photoelec. properties. Ultimately, the PCE exceeds 8% for the first time since 2014, representing the highest efficiency in all kinds of Sb2S3 solar cells to date. This study is expected to shed new light on the fabrication of high-quality Sb2S3 film and further efficiency improvement in Sb2S3 solar cells.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitlGmt7zP&md5=e727b856c498e834c0cf67c2aa1d5e79
  10. 10
    Yang, Z.; Wang, X.; Chen, Y.; Zheng, Z.; Chen, Z.; Xu, W.; Liu, W.; Yang, Y.; Zhao, J.; Chen, T.; Zhu, H. Ultrafast Self-Trapping of Photoexcited Carriers Sets the Upper Limit on Antimony Trisulfide Photovoltaic Devices. Nat. Commun. 2019, 10 (1), 4540,  DOI: 10.1038/s41467-019-12445-6
    Google Scholar
    10
    Ultrafast self-trapping of photoexcited carriers sets the upper limit on antimony trisulfide photovoltaic devices
    Yang Zhaoliang; Chen Yuzhong; Chen Zeng; Zhu Haiming; Wang Xiaomin; Chen Tao; Zheng Zhenfa; Zhao Jin; Xu Wenqi; Liu Weimin; Yang Yang Michael; Zhu Haiming
    Nature communications (2019), 10 (1), 4540 ISSN:.
    Antimony trisulfide (Sb2S3) is considered to be a promising photovoltaic material; however, the performance is yet to be satisfactory. Poor power conversion efficiency and large open circuit voltage loss have been usually ascribed to interface and bulk extrinsic defects By performing a spectroscopy study on Sb2S3 polycrystalline films and single crystal, we show commonly existed characteristics including redshifted photoluminescence with 0.6 eV Stokes shift, and a few picosecond carrier trapping without saturation at carrier density as high as approximately 10(20) cm(-3). These features, together with polarized trap emission from Sb2S3 single crystal, strongly suggest that photoexcited carriers in Sb2S3 are intrinsically self-trapped by lattice deformation, instead of by extrinsic defects. The proposed self-trapping explains spectroscopic results and rationalizes the large open circuit voltage loss and near-unity carrier collection efficiency in Sb2S3 thin film solar cells. Self-trapping sets the upper limit on maximum open circuit voltage (approximately 0.8 V) and thus power conversion efficiency (approximately 16 %) for Sb2S3 solar cells.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BB3Mnlt1ersg%253D%253D&md5=d5811974a141c676264df91df7e68a03
  11. 11
    Tang, R.; Wang, X.; Jiang, C.; Li, S.; Liu, W.; Ju, H.; Yang, S.; Zhu, C.; Chen, T. N-Type Doping of Sb2S3 Light-Harvesting Films Enabling High-Efficiency Planar Heterojunction Solar Cells. ACS Appl. Mater. Interfaces 2018, 10 (36), 30314– 30321,  DOI: 10.1021/acsami.8b08965
    Google Scholar
    11
    n-Type Doping of Sb2S3 Light-Harvesting Films Enabling High-Efficiency Planar Heterojunction Solar Cells
    Tang, Rongfeng; Wang, Xiaomin; Jiang, Chenhui; Li, Shiang; Liu, Weifeng; Ju, Huanxin; Yang, Shangfeng; Zhu, Changfei; Chen, Tao
    ACS Applied Materials & Interfaces (2018), 10 (36), 30314-30321CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
    Sb2S3 is a kind of new light-absorbing material possessing high stability in ambient environment, high absorption coeff. in the visible range, and abundant elemental storage. To improve the power conversion efficiency of Sb2S3-based solar cells, here the authors control the defect in Sb2S3 absorber films. The increase of S vacancy is able to upgrade photovoltaic properties. With the increase in S vacancy, the carrier concns. are increased. This n-type doping gives rise to an upshift of the Fermi level of Sb2S3 so that the charge transport from Sb2S3 to the electron selection material becomes dynamically favorable. The introduction of ZnCl2 in film fabrication is also found to regulate the film growth for enhanced crystallinity. Finally, the photovoltaic parameters, short-circuit c.d., open-circuit voltage, and the fill factor of the device based on the Sb2S3 film are all considerably enhanced, boosting the final power conversion efficiency from 5.15 to 6.35%. This efficiency is the highest value in planar heterojunction Sb2S3 solar cells and among the top values in all kinds of Sb2S3 solar cells. This research provides a fundamental understanding regarding the properties of Sb2S3 and a convenient approach for enhancing the performance of Sb2S3 solar cells.
    >> More from SciFinder ®
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  12. 12
    Jiang, C.; Tang, R.; Wang, X.; Ju, H.; Chen, G.; Chen, T. Alkali Metals Doping for High-Performance Planar Heterojunction Sb2S3 Solar Cells. Solar RRL 2019, 3 (1), 1800272  DOI: 10.1002/solr.201800272
    Google Scholar
    There is no corresponding record for this reference.
  13. 13
    Büttner, P.; Scheler, F.; Pointer, C.; Döhler, D.; Barr, M. K. S.; Koroleva, A.; Pankin, D.; Hatada, R.; Flege, S.; Manshina, A.; Young, E. R.; Mínguez-Bacho, I.; Bachmann, J. Adjusting Interfacial Chemistry and Electronic Properties of Photovoltaics Based on a Highly Pure Sb2S3 Absorber by Atomic Layer Deposition. ACS Appl. Energy Mater. 2019, 2 (12), 8747– 8756,  DOI: 10.1021/acsaem.9b01721
    Google Scholar
    13
    Adjusting Interfacial Chemistry and Electronic Properties of Photovoltaics Based on a Highly Pure Sb2S3 Absorber by Atomic Layer Deposition
    Buettner, Pascal; Scheler, Florian; Pointer, Craig; Doehler, Dirk; Barr, Maissa K. S.; Koroleva, Aleksandra; Pankin, Dmitrii; Hatada, Ruriko; Flege, Stefan; Manshina, Alina; Young, Elizabeth R.; Minguez-Bacho, Ignacio; Bachmann, Julien
    ACS Applied Energy Materials (2019), 2 (12), 8747-8756CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)
    The combination of oxide and heavier chalcogenide layers in thin film photovoltaics suffers limitations assocd. with oxygen incorporation and sulfur deficiency in the chalcogenide layer or with a chem. incompatibility which results in dewetting issues and defect states at the interface. Here, we establish at. layer deposition (ALD) as a tool to overcome these limitations. ALD allows one to obtain highly pure Sb2S3 light absorber layers, and we exploit this technique to generate an addnl. interfacial layer consisting of 1.5 nm ZnS. This ultrathin layer simultaneously resolves dewetting and passivates defect states at the interface. We demonstrate via transient absorption spectroscopy that interfacial electron recombination is one order of magnitude slower at the ZnS-engineered interface than hole recombination at the Sb2S3/P3HT interface. The comparison of solar cells with and without oxide incorporation in Sb2S3, with and without the ultrathin ZnS interlayer, and with systematically varied Sb2S3 thickness provides a complete picture of the phys. processes at work in the devices.
    >> More from SciFinder ®
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  14. 14
    Guo, L.; Zhang, B.; Li, S.; Zhang, Q.; Buettner, M.; Li, L.; Qian, X.; Yan, F. Scalable and Efficient Sb2S3 Thin-Film Solar Cells Fabricated by Close Space Sublimation. APL Materials 2019, 7 (4), 041105  DOI: 10.1063/1.5090773
    Google Scholar
    14
    Scalable and efficient Antimony sulfide thin-film solar cells fabricated by close space sublimation
    Guo, Liping; Zhang, Baiyu; Li, Shan; Zhang, Qian; Buettner, Michael; Li, Lin; Qian, Xiaofeng; Yan, Feng
    APL Materials (2019), 7 (4), 041105/1-041105/6CODEN: AMPADS; ISSN:2166-532X. (American Institute of Physics)
    Antimony sulfide as a cost-effective, low-toxic, and earth-abundant solar cell absorber with the desired bandgap was successfully deposited using a scalable close space sublimation technique. The deposition process can sep. control the substrate and source temp. with better engineering of the absorber quality. The device performance can reach 3.8% with the configuration of glass/FTO/CdS/Sb2S3/graphite back contact. The defect formation energy and the corresponding transition levels were investigated in detail using theor. calcns. Our results suggest that Sb2S3 exhibits intrinsic p-type owing to S-on-Sb antisites (SSb) and the device performance is limited by the S vacancies. The localized conduction characterization at nanoscale shows that the non-cubic Sb2S3 has conductive grains and benign grain boundaries. The study of the defects, microstructure, and nanoscale conduction behavior suggests that Sb2S3 could be a promising photovoltaic candidate for scalable manufg. (c) 2019 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXmslartbk%253D&md5=5d1625d82258b2a83a130babe765faa6
  15. 15
    Eensalu, J. S.; Katerski, A.; Kärber, E.; Oja Acik, I.; Mere, A.; Krunks, M. Uniform Sb2S3 Optical Coatings by Chemical Spray Method. Beilstein J. Nanotechnol. 2019, 10, 198– 210,  DOI: 10.3762/bjnano.10.18
    Google Scholar
    15
    Uniform Sb2S3 optical coatings by chemical spray method
    Eensalu Jako S; Katerski Atanas; Karber Erki; Oja Acik Ilona; Mere Arvo; Krunks Malle
    Beilstein journal of nanotechnology (2019), 10 (), 198-210 ISSN:2190-4286.
    Antimony sulfide (Sb2S3), an environmentally benign material, has been prepared by various deposition methods for use as a solar absorber due to its direct band gap of ≈1.7 eV and high absorption coefficient in the visible light spectrum (1.8 × 10(5) cm(-1) at 450 nm). Rapid, scalable, economically viable and controllable in-air growth of continuous, uniform, polycrystalline Sb2S3 absorber layers has not yet been accomplished. This could be achieved with chemical spray pyrolysis, a robust chemical method for deposition of thin films. We applied a two-stage process to produce continuous Sb2S3 optical coatings with uniform thickness. First, amorphous Sb2S3 layers, likely forming by 3D Volmer-Weber island growth through a molten phase reaction between SbCl3 and SC(NH2)2, were deposited in air on a glass/ITO/TiO2 substrate by ultrasonic spraying of methanolic Sb/S 1:3 molar ratio solution at 200-210 °C. Second, we produced polycrystalline uniform films of Sb2S3 (Eg 1.8 eV) with a post-deposition thermal treatment of amorphous Sb2S3 layers in vacuum at 170 °C, <4 × 10(-6) Torr for 5 minutes. The effects of the deposition temperature, the precursor molar ratio and the thermal treatment temperature on the Sb2S3 layers were investigated using Raman spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and UV-vis-NIR spectroscopy. We demonstrated that Sb2S3 optical coatings with controllable structure, morphology and optical properties can be deposited by ultrasonic spray pyrolysis in air by tuning of the deposition temperature, the Sb/S precursor molar ratio in the spray solution, and the post-deposition treatment temperature.
    >> More from SciFinder ®
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  16. 16
    Choi, Y. C.; Lee, D. U.; Noh, J. H.; Kim, E. K.; Seok, S. I. Highly Improved Sb2S3 Sensitized-Inorganic–Organic Heterojunction Solar Cells and Quantification of Traps by Deep-Level Transient Spectroscopy. Adv. Funct. Mater. 2014, 24 (23), 3587– 3592,  DOI: 10.1002/adfm.201304238
    Google Scholar
    16
    Highly Improved Sb2S3 Sensitized-Inorganic-Organic Heterojunction Solar Cells and Quantification of Traps by Deep-Level Transient Spectroscopy
    Choi, Yong Chan; Lee, Dong Uk; Noh, Jun Hong; Kim, Eun Kyu; Seok, Sang Il
    Advanced Functional Materials (2014), 24 (23), 3587-3592CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
    The light-harvesting Sb2S3 surface on mesoporous-TiO2 in inorg.-org. heterojunction solar cells is sulfurized with thioacetamide (TA). The photovoltaic performances are compared before and after TA treatment, and the state of the Sb2S3 is studied by x-ray diffraction, XPS, and deep-level transient spectroscopy (DLTS). Although there are no differences in crystallinity and compn., the TA-treated solar cells exhibit significantly enhanced performance compared to pristine Sb2S3-sensitized solar cells. From DLTS anal., the performance enhancement is mainly attributed to the extinction of trap sites, which are present at a d. of (2-5) × 1014 cm-3 in Sb2S3, by TA treatment. Through such a simple treatment, the cell records an overall power conversion efficiency (PCE) of 7.5% through a metal mask under simulated illumination (AM 1.5 G, 100 mW cm-2) with a very high open circuit voltage of 711.0 mV. This PCE is, thus far, the highest reported for fully solid-state chalcogenide-sensitized solar cells.
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  17. 17
    European Commission. Communication from the Commission to the European Parliament, The Council, The European Economic and Social Committee and the Committee of the regions Critical Raw Materials Resilience: Charting a Path towards Greater Security and Sustainability, 2020. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52020DC0474.
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    There is no corresponding record for this reference.
  18. 18
    Department of the Interior; Office of the Secretary. Final List of Critical Minerals 2018, 2018. https://www.federalregister.gov/documents/2018/05/18/2018-10667/final-list-of-critical-minerals-2018.
    Google Scholar
    There is no corresponding record for this reference.
  19. 19
    2022 Critical Minerals Strategy, 2022. https://www.industry.gov.au/publications/critical-minerals-strategy-2022.
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    There is no corresponding record for this reference.
  20. 20
    Lee, S.-J.; Sung, S.-J.; Yang, K.-J.; Kang, J.-K.; Kim, J. Y.; Do, Y. S.; Kim, D.-H. Approach to Transparent Photovoltaics Based on Wide Band Gap Sb2S3 Absorber Layers and Optics-Based Device Optimization. ACS Appl. Energy Mater. 2020, 3 (12), 12644– 12651,  DOI: 10.1021/acsaem.0c02552
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    20
    Approach to Transparent Photovoltaics Based on Wide Band Gap Sb2S3 Absorber Layers and Optics-Based Device Optimization
    Lee, Sang-Ju; Sung, Shi-Joon; Yang, Kee-Jeong; Kang, Jin-Kyu; Kim, Jun Yong; Do, Yun Seon; Kim, Dae-Hwan
    ACS Applied Energy Materials (2020), 3 (12), 12644-12651CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)
    Numerous methods have been employed for utilizing inorg. thin films to improve the stability of transparent photovoltaics (TPVs). However, the use of these methods was restricted due to limitations involving restricted phys. dimensions, complex fabrication processes, visible transparency, and photovoltaic performance. In this study, a novel approach to novel TPVs based on wide band gap inorg. thin-film solar cell devices was first proposed. This approach was based on an Sb2S3 thin-film absorber and the optical optimization of a planar-type solar cell device structure. High-quality and uniformly thick Sb2S3 thin films were deposited via at. layer deposition (ALD) to produce a high-quality transparent absorber layer for a planar-type transparent thin-film solar cell. To maintain the light transmittance of ALD-Sb2S3 solar cell devices, a flat indium tin oxide (ITO) substrate, a low-temp.-processed ALD TiO2 electron-transport layer (ETL), and an ultrathin Au top electrode were systematically combined with the transparent ALD-Sb2S3 absorber layer. The transparent ALD-Sb2S3 solar cell device showed a power conversion efficiency of 3.44% and an av. light transmittance of 13%. These results proposed the technol. possibility of using novel inorg. transparent Sb2S3 solar cell devices for transparent applications, such as self-powered transparent displays, high-efficiency tandem solar cells, robust bifacial solar cells, and so on.
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  21. 21
    Kumar, P.; You, S.; Vomiero, A. CuSCN as a Hole Transport Layer in an Inorganic Solution-Processed Planar Sb2S3 Solar Cell, Enabling Carbon-Based and Semitransparent Photovoltaics. J. Mater. Chem. C 2022, 10 (43), 16273– 16282,  DOI: 10.1039/D2TC03420D
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    CuSCN as a hole transport layer in an inorganic solution-processed planar Sb2S3 solar cell, enabling carbon-based and semitransparent photovoltaics
    Kumar, Pankaj; You, Shujie; Vomiero, Alberto
    Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2022), 10 (43), 16273-16282CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
    Sb2S3 is an emerging inorg. photovoltaic absorber material with attractive properties such as high absorption coeff., stability, earth-abundance, non-toxicity, and low-temp. soln. processability. Furthermore, with a bandgap of ca. 1.7 eV, it can also be used in semitransparent or tandem solar cell applications. Here, an inorg. wide-bandgap hole transport layer (HTL), copper thiocyanate (CuSCN), is used in an Sb2S3 solar cell employing a simple planar geometry. The compact and highly transparent CuSCN HTL was compatible with the low-cost, blade-coated carbon/Ag electrode and a semitransparent solar cell device. With Au and carbon/Ag electrodes, chem. bath deposited Sb2S3 solar cells achieved power conversion efficiencies (PCEs) of 1.75% and 1.95%, resp. At the same time, a preliminary semitransparent Sb2S3 device with an ultrathin Au (∼15 nm) electrode showed a good av. visible transmittance (AVT) of 26.7% at a PCE of 1.65%.
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  22. 22
    Han, J.; Pu, X.; Zhou, H.; Cao, Q.; Wang, S.; He, Z.; Gao, B.; Li, T.; Zhao, J.; Li, X. Synergistic Effect through the Introduction of Inorganic Zinc Halides at the Interface of TiO2 and Sb2S3 for High-Performance Sb2S3 Planar Thin-Film Solar Cells. ACS Appl. Mater. Interfaces 2020, 12 (39), 44297– 44306,  DOI: 10.1021/acsami.0c11550
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    Synergistic Effect through the Introduction of Inorganic Zinc Halides at the Interface of TiO2 and Sb2S3 for High-Performance Sb2S3 Planar Thin-Film Solar Cells
    Han, Jian; Pu, Xingyu; Zhou, Hui; Cao, Qi; Wang, Shuangjie; He, Ziwei; Gao, Bingyu; Li, Tongtong; Zhao, Junsong; Li, Xuanhua
    ACS Applied Materials & Interfaces (2020), 12 (39), 44297-44306CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
    The competition between charge recombination and extn. principally affects the fill factor (FF) and power conversion efficiency (PCE) of planar thin-film solar cells. In Sb2S3 thin-film solar cells, the electrocharge recombination and extn. n transport layer (ETL) plays a significant role in electron extn. and detn. of Sb2S3 film absorber quality. Herein, a TiO2 ETL is strategically modified using an inorg. salt zinc halide (i.e., ZnCl2, ZnBr2, ZnI2), which simultaneously improves the electronic properties of TiO2 and promotes the growth of Sb2S3 films with larger grain size and higher crystallinity. The exptl. results and theor. calcns. further reveal that the zinc halide can interact with TiO2 and simultaneously bond strongly with the upper Sb2S3 film, which creates a unique pathway for electron transfer, passivates the trap states, and alleviates the recombination losses effectively. As a result, an av. PCE of 6.87 ± 0.11% and the highest PCE of 7.08% have been attained with an improved FF from 51.22 to 61.61% after ZnCl2 introduction. Addnl., introduction of ZnCl2 helps the unencapsulated devices to maintain 93% of their original performance after 2400 h of storage in a nitrogen-filled glovebox. This work develops an effective route for the optimization of ETLs and defect healing using simple and low-cost inorg. salts.
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  23. 23
    Han, J.; Wang, S.; Yang, J.; Guo, S.; Cao, Q.; Tang, H.; Pu, X.; Gao, B.; Li, X. Solution-Processed Sb2S3 Planar Thin Film Solar Cells with a Conversion Efficiency of 6.9% at an Open Circuit Voltage of 0.7 V Achieved via Surface Passivation by a SbCl3 Interface Layer. ACS Appl. Mater. Interfaces 2020, 12 (4), 4970– 4979,  DOI: 10.1021/acsami.9b15148
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    23
    Solution-Processed Sb2S3 Planar Thin Film Solar Cells with a Conversion Efficiency of 6.9% at an Open Circuit Voltage of 0.7 V Achieved via Surface Passivation by a SbCl3 Interface Layer
    Han, Jian; Wang, Shuangjie; Yang, Jiabao; Guo, Shaohui; Cao, Qi; Tang, Huijie; Pu, Xingyu; Gao, Bingyu; Li, Xuanhua
    ACS Applied Materials & Interfaces (2020), 12 (4), 4970-4979CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
    Interfaces in Sb2S3 thin film solar cells strongly affect their open-circuit voltage (VOC) and power conversion efficiency (PCE). Finding an effective method of reducing the defects is a promising approach for increasing the VOC and PCE. Herein, the use of an inorg. salt SbCl3 is reported for post-treatment on Sb2S3 films for surface passivation. It is found that a thin SbCl3 layer could form on the Sb2S3 surface and produce higher-efficiency cells by reducing the defects and suppressing nonradiative recombination. Through d. functional theory calcns., it is found that the passivation of the Sb2S3 surface by SbCl3 occurs via the interactions of Sb and Cl in SbCl3 mols. with S and Sb in Sb2S3, resp. As a result, incorporating the SbCl3 layer highly improves the VOC from 0.58 to 0.72 V; and an av. PCE of 6.9±0.1% and a highest PCE of 7.1% is obtained with an area of 0.1 cm2. The achieved PCE is the highest value in the Sb2S3 planar solar cells. In addn., the incorporated SbCl3 layer also leads to a good stability of Sb2S3 devices, by which 90% of initial performance is maintained for 1080 h storage under ambient humidity (85±5% relative humidity) at room temp.
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  24. 24
    Li, J.; Liu, X.; Yao, J. The Enhanced Photovoltaic Performance of Sb2S3 Solar Cells by Thermal Decomposition of Antimony Ethyl Xanthate with Thiourea Doping. Energy Technology 2020, 8 (4), 1900841,  DOI: 10.1002/ente.201900841
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    The Enhanced Photovoltaic Performance of Antimony trisulfide Solar Cells by Thermal Decomposition of Antimony Ethyl Xanthate with Thiourea Doping
    Li, Jihong; Liu, Xiaolong; Yao, Jianxi
    Energy Technology (Weinheim, Germany) (2020), 8 (4), 1900841CODEN: ETNEFN; ISSN:2194-4296. (Wiley-VCH Verlag GmbH & Co. KGaA)
    The thermal decompn. method is regarded as a simple and effective way to prep. Sb2S3 films. Herein, Antimony trisulfide films are prepd. by thermal decompns. of antimony Et xanthate (Sb(xt)3). During the thermal decompns. process, sulfur vacancy defects are easily formed because of high temps. To reduce the sulfur vacancy defects in the final Sb2S3 films, thiourea (TU) is introduced in the Sb(xt) precursor. By doping with TU, the crystallinity of the Sb2S3 films improves and dense Sb2S3 films are formed. With the decrease in sulfur defects, the carrier concns. are greatly increased from 2.5 × 1016 to 6.2 × 1016 cm-3. Compared with the no-doping Sb2S3 solar cells, the power conversion efficiency of Sb2S3 solar cells with doping 25% TU is improved from 2.85% to 3.70%.
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  25. 25
    Eensalu, J. S.; Tõnsuaadu, K.; Oja Acik, I.; Krunks, M. Sb2S3 Thin Films by Ultrasonic Spray Pyrolysis of Antimony Ethyl Xanthate. Mater. Sci. Semicond. Process. 2022, 137, 106209  DOI: 10.1016/j.mssp.2021.106209
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    25
    Sb2S3 thin films by ultrasonic spray pyrolysis of antimony ethyl xanthate
    Eensalu, Jako S.; Tonsuaadu, Kaia; Oja Acik, Ilona; Krunks, Malle
    Materials Science in Semiconductor Processing (2022), 137 (), 106209CODEN: MSSPFQ; ISSN:1369-8001. (Elsevier Ltd.)
    Synthesis of antimony chalcogenides, esp. Sb2S3, by facile and area scalable in-air chem. methods, such as spray pyrolysis, from cost-effective chems. is certain to accelerate development of the related thin film solar cell technol. In this study, antimony Et xanthate, a scarcely studied halogenide-free precursor, is proven to be suitable for the deposition of conformal phase pure cryst. Sb2S3thin films via ultrasonic spray pyrolysis in air by a two-step process. First, a soln. of antimony Et xanthate with thiourea in a molar ratio of 1/3, or with thioacetamide in a molar ratio of 1/10 was sprayed onto a glass/ITO/TiO2 substrate by ultrasonic spray pyrolysis at 215°C to yield amorphous phase pure Sb2S3thin films. Second, performing post-growth heat treatment in vacuum at 225°C, was the key to produce phase pure conformal thin films of cryst. Sb2S3(Eg 1.8 eV) with S/Sb at. ratio of 1.46 by using thiourea, and 1.41 by using thioacetamide, resp. Spraying solns. of antimony Et xanthate at ≥135°C resulted in the formation of the Sb2O3 phase. Adding thiourea or thioacetamide to the spray soln. prevented the oxidn. of the growing Sb2S3layer during deposition at 135°C, 165°C, and 215°C. The suppressed oxidn. of Sb2S3layers is attributed to the liq. state of thiourea and thioacetamide in these conditions.
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  26. 26
    Eensalu, J. S.; Katerski, A.; Kärber, E.; Weinhardt, L.; Blum, M.; Heske, C.; Yang, W.; Oja Acik, I.; Krunks, M. Semitransparent Sb2S3 Thin Film Solar Cells by Ultrasonic Spray Pyrolysis for Use in Solar Windows. Beilstein J. Nanotechn. 2019, 10, 2396– 2409,  DOI: 10.3762/bjnano.10.230
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    There is no corresponding record for this reference.
  27. 27
    Tamm, A.; Acik, I. O.; Arroval, T.; Kasikov, A.; Seemen, H.; Marandi, M.; Krunks, M.; Mere, A.; Kukli, K.; Aarik, J. Plasmon Resonance Effect Caused by Gold Nanoparticles Formed on Titanium Oxide Films. Thin Solid Films 2016, 616, 449– 455,  DOI: 10.1016/j.tsf.2016.08.059
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    27
    Plasmon resonance effect caused by gold nanoparticles formed on titanium oxide films
    Tamm, Aile; Acik, Ilona Oja; Arroval, Tonis; Kasikov, Aarne; Seemen, Helina; Marandi, Margus; Krunks, Malle; Mere, Arvo; Kukli, Kaupo; Aarik, Jaan
    Thin Solid Films (2016), 616 (), 449-455CODEN: THSFAP; ISSN:0040-6090. (Elsevier B.V.)
    Gold nanoparticles were distributed by spray pyrolysis technique on bare glass substrates and on glass covered by titanium dioxide thin films grown by at. layer deposition, and were embedded in titanium dioxide layers. Plasmonic absorption was detected in the visible spectral range. The particles deposited on glass and on 80 nm thick titanium dioxide film resulted in appearance of an absorption band peaking at 550 nm. The plasmonic absorption maxima shifted towards longer wavelengths after embedding the particles into a top TiO2 layer. Atomic layer deposition of TiO2 films assisted in fixing and sepg. the metal particles on the surface, without destructive influence on the plasmonic behavior.
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  28. 28
    Hobson, T. D. C.; Durose, K. Protocols for the Miller Indexing of Sb2Se3 and a Non-x-Ray Method of Orienting Its Single Crystals. Mater. Sci. Semicond. Process. 2021, 127, 105691  DOI: 10.1016/j.mssp.2021.105691
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    Protocols for the Miller indexing of Sb2Se3 and a non-x-ray method of orienting its single crystals
    Hobson, T. D. C.; Durose, K.
    Materials Science in Semiconductor Processing (2021), 127 (), 105691CODEN: MSSPFQ; ISSN:1369-8001. (Elsevier Ltd.)
    The Sb2Se3 is a highly anisotropic semiconductor and unambiguous Miller indexing of its planes and diffraction patterns is therefore important - as is the prepn. of oriented and indexed surfaces of single crystals for fundamental studies. The purpose of this letter is twofold: (a) to bring attention to the two different Miller indexing conventions in popular use for Sb2Se3, (Space group No. 62, settings Pnma and Pbnm) explaining how they are related to its crystal structure and making recommendations for reporting protocols, and (b) to draw attention to a non-x-ray method of prepg. the three {100} type faces of single crystals of Sb2Se3 for use in phys. investigations.
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  29. 29
    Whittles, T. J.; Burton, L. A.; Skelton, J. M.; Walsh, A.; Veal, T. D.; Dhanak, V. R. Band Alignments, Valence Bands, and Core Levels in the Tin Sulfides SnS, SnS2, and Sn2S3: Experiment and Theory. Chem. Mater. 2016, 28 (11), 3718– 3726,  DOI: 10.1021/acs.chemmater.6b00397
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    29
    Band Alignments, Valence Bands, and Core Levels in the Tin Sulfides SnS, SnS2, and Sn2S3: Experiment and Theory
    Whittles, Thomas J.; Burton, Lee A.; Skelton, Jonathan M.; Walsh, Aron; Veal, Tim D.; Dhanak, Vin R.
    Chemistry of Materials (2016), 28 (11), 3718-3726CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
    Tin sulfide solar cells show relatively poor efficiencies despite attractive photovoltaic properties, and there is difficulty in identifying sep. phases, which are also known to form during Cu2ZnSnS4 depositions. The authors present x-ray photoemission spectroscopy (XPS) and inverse photoemission spectroscopy measurements of single crystal SnS, SnS2, and Sn2S3, with electronic-structure calcns. from d. functional theory (DFT). Differences in the XPS spectra of the three phases, including a large 0.9 eV shift between the 3d5/2 peak for SnS and SnS2, make this technique useful when identifying phase-pure or mixed-phase systems. Comparison of the valence band spectra from XPS and DFT reveals extra states at the top of the valence bands of SnS and Sn2S3, arising from the hybridization of lone pair electrons in Sn(II), which are not present for Sn(IV), as found in SnS2. This results in relatively low ionization potentials for SnS (4.71 eV) and Sn2S3 (4.66 eV), giving a more comprehensive explanation as to the origin of the poor efficiencies. The authors also demonstrate, by a band alignment, the large band offsets of SnS and Sn2S3 from other photovoltaic materials and highlight the detrimental effect on cell performance of secondary tin sulfide phase formation in SnS and CZTS films.
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  30. 30
    Chernenko, K.; Kivimaki, A.; Parna, R.; Wang, W.; Sankari, R.; Leandersson, M.; Tarawneh, H.; Pankratov, V.; Kook, M.; Kukk, E.; Reisberg, L.; Urpelainen, S.; Kaambre, T.; Siewert, F.; Gwalt, G.; Sokolov, A.; Lemke, S.; Alimov, S.; Knedel, J.; Kutz, O.; Seliger, T.; Valden, M.; Hirsimaki, M.; Kirm, M.; Huttula, M. Performance and Characterization of the FinEstBeAMS Beamline at the MAX IV Laboratory. J. Synchrotron Radiat. 2021, 28, 1620– 1630,  DOI: 10.1107/S1600577521006032
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    30
    Performance and characterization of the FinEstBeAMS beamline at the MAX IV Laboratory
    Chernenko, Kirill; Kivimaeki, Antti; Paerna, Rainer; Wang, Weimin; Sankari, Rami; Leandersson, Mats; Tarawneh, Hamed; Pankratov, Vladimir; Kook, Mati; Kukk, Edwin; Reisberg, Liis; Urpelainen, Samuli; Kaeaembre, Tanel; Siewert, Frank; Gwalt, Grzegorz; Sokolov, Andrey; Lemke, Stephanie; Alimov, Svyatoslav; Knedel, Jeniffa; Kutz, Oliver; Seliger, Tino; Valden, Mika; Hirsimaeki, Mika; Kirm, Marco; Huttula, Marko
    Journal of Synchrotron Radiation (2021), 28 (5), 1620-1630CODEN: JSYRES; ISSN:1600-5775. (International Union of Crystallography)
    FinEstBeAMS (Finnish-Estonian Beamline for Atm. and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5 GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5-1300 eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazing-incidence plane grating monochromator to disperse the radiation. At photon energies below 70 eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examg. such characteristics as the quality of the gratings, photon energy calibration, photon energy resoln., available photon flux, polarization quality and focal spot size.
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  31. 31
    Zakaznova-Herzog, V. P.; Harmer, S. L.; Nesbitt, H. W.; Bancroft, G. M.; Flemming, R.; Pratt, A. R. High Resolution XPS Study of the Large-Band-Gap Semiconductor Stibnite (Sb2S3): Structural Contributions and Surface Reconstruction. Surf. Sci. 2006, 600 (2), 348– 356,  DOI: 10.1016/j.susc.2005.10.034
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    31
    High resolution XPS study of the large-band-gap semiconductor stibnite (Sb2S3): Structural contributions and surface reconstruction
    Zakaznova-Herzog, V. P.; Harmer, S. L.; Nesbitt, H. W.; Bancroft, G. M.; Flemming, R.; Pratt, A. R.
    Surface Science (2006), 600 (2), 348-356CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)
    Conventional XPS and synchrotron radiation XPS (SRXPS) were used to probe the chem. state properties of stibnite (Sb2S3), a large-band-gap semiconductor of complex structure. The conventional spectra were obtained with a Kratos Axis Ultra XPS with magnetic confinement charge neutralization, which is very effective in minimizing both uniform charging and differential charging on this large-band-gap semiconductor. The narrow linewidths (much narrower than previously obtained) for single doublet fits (e.g. Sb 4d5/2 of 0.57 eV and S 2p3/2 of 0.63 eV) enabled the observation of a small peak on the low binding energy side of the Sb 3d and Sb 4d lines. With the aid of the very surface-sensitive Sb 4d SRXPS spectra, these low energy peaks are assigned to small Sb metal clusters at the surface after cleavage; the signal for these clusters increases with x-ray dose on the sample. A detailed anal. of the Sb 4d and S 2p linewidths concludes that the Sb 4d5/2 linewidth is larger than expected based on the inherent linewidth of the instrument and the Sb 4d lifetime width, and on comparison with the As 3d linewidth (0.52 eV) for the analogous As2S3. Also, the S 2p3/2 linewidth is substantially broader than the Sb 4d5/2 linewidth. These larger than expected linewidths are due to two structurally distinct Sb atoms and three structurally distinct S atoms in the Sb2S3 crystal structure. Accordingly, the Sb 4d and S 2p spectra were fitted to two and three doublets, resp., and the linewidth for all peaks is 0.53 eV. Using recent MO calcns., the doublets were assigned to the different structural Sb and S sites.
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  32. 32
    Hobson, T. D. C.; Phillips, L. J.; Hutter, O. S.; Durose, K.; Major, J. D. Defect Properties of Sb2Se3 Thin Film Solar Cells and Bulk Crystals. Appl. Phys. Lett. 2020, 116 (26), 261101,  DOI: 10.1063/5.0012697
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    32
    Defect properties of Sb2Se3 thin film solar cells and bulk crystals
    Hobson, Theodore D. C.; Phillips, Laurie J.; Hutter, Oliver S.; Durose, K.; Major, Jonathan D.
    Applied Physics Letters (2020), 116 (26), 261101CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    As an absorber in photovoltaic devices, Sb2Se3 has rapidly achieved impressive power conversion efficiencies despite the lack of fundamental knowledge about its electronic defects. Here, we present a deep level transient spectroscopy (DLTS) study of deep level defects in both bulk crystal and thin film device material. DLTS study of Bridgman-grown n-type bulk crystals revealed traps at 358, 447, 505, and 685 meV below the conduction band edge. Of these, the energetically close pair at 447 and 505 meV could only be resolved using the isothermal transient spectroscopy (rate window variation) method. A completed Sb2Se3 thin film solar cell displayed similar trap spectra with traps identified at 378, 460, and 690 meV. The comparable nature of defects in thin film and bulk crystal material implies that there is minimal impact of polycrystallinity in Sb2Se3 supporting the concept of benign grain boundaries. (c) 2020 American Institute of Physics.
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  33. 33
    Eensalu, J. S.; Tõnsuaadu, K.; Adamson, J.; Oja Acik, I.; Krunks, M. Thermal Decomposition of Tris(O-Ethyldithiocarbonato)-Antimony(III)─a Single-Source Precursor for Antimony Sulfide Thin Films. J. Therm. Anal. Calorim. 2022, 147 (8), 4899– 4913,  DOI: 10.1007/s10973-021-10885-1
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    33
    Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III)-a single-source precursor for antimony sulfide thin films
    Eensalu, Jako S.; Tonsuaadu, Kaia; Adamson, Jasper; Oja Acik, Ilona; Krunks, Malle
    Journal of Thermal Analysis and Calorimetry (2022), 147 (8), 4899-4913CODEN: JTACF7; ISSN:1388-6150. (Springer)
    Thermal decompn. of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aq. soln. of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, DTA and evolved gas anal. via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform IR spectroscopy (FTIR) and NMR (NMR) measurements, and quantified by NMR and elemental anal. Solid intermediates and final decompn. products of 1 prepd. in both atmospheres were detd. by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compd., where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degrdn. of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomps. at 90-170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO22- ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decompn. mechanism of 1 is described with chem. reactions based on EGA-MS and solid intermediate decompn. product anal.
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  34. 34
    Kärber, E.; Katerski, A.; Oja Acik, I.; Mere, A.; Mikli, V.; Krunks, M. Sb2S3 Grown by Ultrasonic Spray Pyrolysis and Its Application in a Hybrid Solar Cell. Beilstein J. Nanotechnol. 2016, 7, 1662– 1673,  DOI: 10.3762/bjnano.7.158
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    34
    Sb2S3 grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell
    Karber, Erki; Katerski, Atanas; Acik, Ilona Oja; Mere, Arvo; Mikli, Valdek; Krunks, Malle
    Beilstein Journal of Nanotechnology (2016), 7 (), 1662-1673CODEN: BJNEAH; ISSN:2190-4286. (Beilstein-Institut zur Foerderung der Chemischen Wissenschaften)
    Chem. spray pyrolysis (CSP) is a fast wet-chem. deposition method in which an aerosol is guided by carrier gas onto a hot substrate where the decompn. of the precursor chems. occurs. The aerosol is produced using an ultrasonic oscillator in a bath of precursor soln. and guided by compressed air. The use of the ultrasonic CSP resulted in the growth of homogeneous and well-adhered layers that consist of submicron crystals of single-phase Sb2S3 with a bandgap of 1.6 eV if an abundance of sulfur source is present in the precursor soln. (SbCl3/SC(NH2)2 = 1:6) sprayed onto the substrate at 250 °C in air. Solar cells with glass-ITO-TiO2-Sb2S3-P3HT-Au structure and an active area of 1 cm2 had an open circuit voltage of 630 mV, short circuit c.d. of 5 mA/cm2, a fill factor of 42% and a conversion efficiency of 1.3%. Conversion efficiencies up to 1.9% were obtained from solar cells with smaller areas.
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  35. 35
    Don, C. H.; Shiel, H.; Hobson, T. D. C.; Savory, C. N.; Swallow, J. E. N.; Smiles, M. J.; Jones, L. A. H.; Featherstone, T. J.; Thakur, P. K.; Lee, T.-L.; Durose, K.; Major, J. D.; Dhanak, V. R.; Scanlon, D. O.; Veal, T. D. Sb 5s2 Lone Pairs and Band Alignment of Sb2Se3: A Photoemission and Density Functional Theory Study. J. Mater. Chem. C 2020, 8 (36), 12615– 12622,  DOI: 10.1039/D0TC03470C
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    35
    Sb 5s2 lone pairs and band alignment of Sb2Se3: a photoemission and density functional theory study
    Don, Christopher H.; Shiel, Huw; Hobson, Theodore D. C.; Savory, Christopher N.; Swallow, Jack E. N.; Smiles, Matthew J.; Jones, Leanne A. H.; Featherstone, Thomas J.; Thakur, Pardeep K.; Lee, Tien-Lin; Durose, Ken; Major, Jonathan D.; Dhanak, Vinod R.; Scanlon, David O.; Veal, Tim D.
    Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2020), 8 (36), 12615-12622CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
    The presence of a lone pair of 5s electrons at the valence band max. (VBM) of Sb2Se3 and the resulting band alignments are investigated using soft and hard X-ray photoemission spectroscopy in parallel with d. functional theory (DFT) calcns. Vacuum-cleaved and exfoliated bulk crystals of Sb2Se3 are analyzed using lab. and synchrotron X-ray sources to acquire high resoln. valence band spectra with both soft and hard X-rays. Utilizing the photon-energy dependence of different orbital cross-sections and corresponding DFT calcns., the various orbital contributions to the valence band could be identified, including the 5s orbital's presence at the VBM. The ionization potential is also detd. and places the VBM at 5.13 eV below the vacuum level, similar to other materials with 5s2 lone pairs, but far above those of related materials without lone pairs of electrons.
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  36. 36
    Zhao, Y.; Wang, S.; Li, C.; Che, B.; Chen, X.; Chen, H.; Tang, R.; Wang, X.; Chen, G.; Wang, T.; Gong, J.; Chen, T.; Xiao, X.; Li, J. Regulating Deposition Kinetics via a Novel Additive-Assisted Chemical Bath Deposition Technology Enables Fabrication of 10.57%-Efficiency Sb2Se3 Solar Cells. Energy Environ. Sci. 2022, 15, 5118,  DOI: 10.1039/D2EE02261C
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    36
    Regulating deposition kinetics via a novel additive-assisted chemical bath deposition technology enables fabrication of 10.57%-efficiency Sb2Se3 solar cells
    Zhao, Yuqi; Wang, Shaoying; Li, Chuang; Che, Bo; Chen, Xueling; Chen, Hongyi; Tang, Rongfeng; Wang, Xiaomin; Chen, Guilin; Wang, Ti; Gong, Junbo; Chen, Tao; Xiao, Xudong; Li, Jianmin
    Energy & Environmental Science (2022), 15 (12), 5118-5128CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
    Synthesizing high-quality films with superior morphol., elec., and defect properties is the basic requirement for obtaining high-efficiency solar cells. Recently, Sb2Se3 has been the emerging photovoltaic material with a low-symmetry crystal structure and complicated defect properties, giving a unique synthesis challenge for high-performance solar devices. In this work, we developed a novel additive-assisted chem. bath deposition (CBD) technol. for producing ideal antimony triselenide (Sb2Se3) films using antimony potassium tartrate and sodium selenosulfate as antimony and selenide sources, resp., with thiourea and selenourea as additives to manipulate the deposition process. We uncover that additive regulated deposition kinetics is essential to improve the film properties. Comprehensively, the phys. properties of Sb2Se3 films in terms of morphol., crystallinity, carrier transport properties, and defect d. have been significantly enhanced. As a result, we achieved a power conversion efficiency of 10.57% in Sb2Se3 solar cells, which represents the highest efficiency of Sb2Se3 solar cells, regardless of the fabrication methods and device structures. Given the scalability to large area prodn. and the low-cost fabrication characteristics of the CBD technique, this study demonstrates not only an effective and implementable method for fabricating highly efficient Sb2Se3 solar cells but also paves the way for industrial prodn. of large-area Sb2Se3 photovoltaic panels in the future.
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  37. 37
    Shiel, H.; Hobson, T. D. C.; Hutter, O. S.; Phillips, L. J.; Smiles, M. J.; Jones, L. A. H.; Featherstone, T. J.; Swallow, J. E. N.; Thakur, P. K.; Lee, T.-L.; Major, J. D.; Durose, K.; Veal, T. D. Band Alignment of Sb2O3 and Sb2Se3. J. Appl. Phys. (Melville, NY, U. S.) 2021, 129 (23), 235301,  DOI: 10.1063/5.0055366
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    37
    Band alignment of Sb2O3 and Sb2Se3
    Shiel, Huw; Hobson, Theodore D. C.; Hutter, Oliver S.; Phillips, Laurie J.; Smiles, Matthew J.; Jones, Leanne A. H.; Featherstone, Thomas J.; Swallow, Jack E. N.; Thakur, Pardeep K.; Lee, Tien-Lin; Major, Jonathan D.; Durose, Ken; Veal, Tim D.
    Journal of Applied Physics (Melville, NY, United States) (2021), 129 (23), 235301CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
    Antimony selenide (Sb2Se3) possesses great potential in the field of photovoltaics (PV) due to its suitable properties for use as a solar absorber and good prospects for scalability. Previous studies have reported the growth of a native antimony oxide (Sb2O3) layer at the surface of Sb2Se3 thin films during deposition and exposure to air, which can affect the contact between Sb2Se3 and subsequent layers. In this study, photoemission techniques were utilized on both Sb2Se3 bulk crystals and thin films to investigate the band alignment between Sb2Se3 and the Sb2O3 layer. By subtracting the valence band spectrum of an in situ cleaved Sb2Se3 bulk crystal from that of the atmospherically contaminated bulk crystal, a valence band offset (VBO) of - 1.72 eV is measured between Sb2Se3 and Sb2O3. This result is supported by a - 1.90 eV VBO measured between Sb2O3 and Sb2Se3 thin films via the Kraut method. Both results indicate a straddling alignment that would oppose carrier extn. through the back contact of superstrate PV devices. This work yields greater insight into the band alignment of Sb2O3 at the surface of Sb2Se3 films, which is crucial for improving the performance of these PV devices. (c) 2021 American Institute of Physics.
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  38. 38
    Fleck, N.; Hutter, O. S.; Phillips, L. J.; Shiel, H.; Hobson, T. D. C.; Dhanak, V. R.; Veal, T. D.; Jäckel, F.; Durose, K.; Major, J. D. How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells. ACS Appl. Mater. Interfaces 2020, 12 (47), 52595– 52602,  DOI: 10.1021/acsami.0c14256
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    38
    How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells
    Fleck, Nicole; Hutter, Oliver S.; Phillips, Laurie J.; Shiel, Huw; Hobson, Theodore D. C.; Dhanak, Vin R.; Veal, Tim D.; Jackel, Frank; Durose, Ken; Major, Jonathan D.
    ACS Applied Materials & Interfaces (2020), 12 (47), 52595-52602CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
    The improvement of antimony selenide solar cells by short-term air exposure is explained using complementary cell and material studies. We demonstrate that exposure to air yields a relative efficiency improvement of n-type Sb2Se3 solar cells of ca. 10% by oxidn. of the back surface and a redn. in the back contact barrier height (measured by J-V-T) from 320 to 280 meV. XPS measurements of the back surface reveal that during 5 days in air, Sb2O3 content at the sample surface increased by 27%, leaving a more Se-rich Sb2Se3 film along with a 4% increase in elemental Se. Conversely, exposure to 5 days of vacuum resulted in a loss of Se from the Sb2Se3 film, which increased the back contact barrier height to 370 meV. Inclusion of a thermally evapd. thin film of Sb2O3 and Se at the back of the Sb2Se3 absorber achieved a peak solar cell efficiency of 5.87%. These results demonstrate the importance of a Se-rich back surface for high-efficiency devices and the pos. effects of an ultrathin antimony oxide layer. This study reveals a possible role of back contact etching in exposing a beneficial back surface and provides a route to increasing device efficiency.
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  39. 39
    Castner, D. G.; Hinds, K.; Grainger, D. W. X-Ray Photoelectron Spectroscopy Sulfur 2p Study of Organic Thiol and Disulfide Binding Interactions with Gold Surfaces. Langmuir 1996, 12 (21), 5083– 5086,  DOI: 10.1021/la960465w
    Google Scholar
    39
    X-ray Photoelectron Spectroscopy Sulfur 2p Study of Organic Thiol and Disulfide Binding Interactions with Gold Surfaces
    Castner, David G.; Hinds, Kenneth; Grainger, David W.
    Langmuir (1996), 12 (21), 5083-5086CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
    The presence of 2 S species was detected in XPS studies of thiol and disulfide mols. adsorbed on Au surfaces. These species are assigned to bound thiolate (S2p3/2 binding energy 162 eV) and unbound thiol/disulfide (S2p3/2 binding energy from 163.5 to 164 eV). These assignments are consistent with XPS data obtained from different thiols (C12, C16, C18, and C22 alkane thiols, a fluorinated thiol, and a cyclic siloxanethiol) and different adsorption conditions (solvent type, thiol concn., temp., and rinsing). In particular, the use of a poor solvent for thiol adsorption solns. (e.g., EtOH for long chain alkanethiols) and the lack of a rinsing step both resulted in unbound thiol mols. present at the surface of the bound thiolate monolayer. This has implications for recent studies asserting the presence of multiple binding sites for Au-thiolate species in org. monolayers.
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  40. 40
    Hobson, T. D. C.; Shiel, H.; Savory, C. N.; Swallow, J. E. N.; Jones, L. A. H.; Featherstone, T. J.; Smiles, M. J.; Thakur, P. K.; Lee, T.-L.; Das, B.; Leighton, C.; Zoppi, G.; Dhanak, V. R.; Scanlon, D. O.; Veal, T. D.; Durose, K.; Major, J. D. P-Type Conductivity in Sn-Doped Sb2Se3. J. Phys.: Energy 2022, 4 (4), 045006  DOI: 10.1088/2515-7655/ac91a6
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    There is no corresponding record for this reference.
  41. 41
    Yin, Y.; Wu, C.; Tang, R.; Jiang, C.; Jiang, G.; Liu, W.; Chen, T.; Zhu, C. Composition Engineering of Sb2S3 Film Enabling High Performance Solar Cells. Sci. Bull. 2019, 64 (2), 136– 141,  DOI: 10.1016/j.scib.2018.12.013
    Google Scholar
    41
    Composition engineering of Sb2S3 film enabling high performance solar cells
    Yin, Yiwei; Wu, Chunyan; Tang, Rongfeng; Jiang, Chenhui; Jiang, Guoshun; Liu, Weifeng; Chen, Tao; Zhu, Changfei
    Science Bulletin (2019), 64 (2), 136-141CODEN: SBCUA5; ISSN:2095-9281. (Elsevier B.V.)
    Sb2S3 is a kind of stable light absorption materials with suitable band gap, promising for practical applications. Here we demonstrate that the engineering on the compn. ratio enables significant improvement in the device performance. We found that the co-evapn. of sulfur or antimony with Sb2S3 is able to generate sulfur- or antimony-rich Sb2S3. This compn. does not generate essential influence on the crystal structure, optical band and film formability, while the carrier concn. and transport dynamics are considerably changed. The device investigations show that sulfur-rich Sb2S3 film is favorable for efficient energy conversion, while antimony-rich Sb2S3 leads to greatly decreased device performance. With optimizations on the sulfur-rich Sb2S3 films, the final power conversion efficiency reaches 5.8%, which is the highest efficiency in thermal evapn. derived Sb2S3 solar cells.
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  42. 42
    Darga, A.; Mencaraglia, D.; Longeaud, C.; Savenije, T. J.; O’Regan, B.; Bourdais, S.; Muto, T.; Delatouche, B.; Dennler, G. On Charge Carrier Recombination in Sb2S3 and Its Implication for the Performance of Solar Cells. J. Phys. Chem. C 2013, 117 (40), 20525– 20530,  DOI: 10.1021/jp4072394
    Google Scholar
    42
    On charge carrier recombination in Sb2S3 and its implication for the performance of solar cells
    Darga, Arouna; Mencaraglia, Denis; Longeaud, Christophe; Savenije, Tom J.; O'Regan, Brian; Bourdais, Stephane; Muto, Takuma; Delatouche, Bruno; Dennler, Gilles
    Journal of Physical Chemistry C (2013), 117 (40), 20525-20530CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
    Sb2S3 is widely considered to be an attractive photovoltaic material based on abundant, nontoxic elements. However, the max. efficiency reported for solar cells based on this semiconductor does not exceed 6.5%. We have measured light intensity-dependent J-V curves, transient microwave photocond., steady-state photocurrent grating, modulated photocurrent, and photocond. on Sb2S3-based samples. All techniques converge toward the same observation: the main recombination route controlling the d. of charge carriers in the absorber is of an order greater than one and appears to stem from an exponentially decaying d. of tail states within the conduction band of the material. This conclusion has direct and drastic implications for the performance of Sb2S3-based solar cells.
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  43. 43
    Rau, U.; Schock, H. W. Electronic Properties of Cu(In,Ga)Se2 Heterojunction Solar Cells–Recent Achievements, Current Understanding, and Future Challenges. Appl. Phys. A: Mater. Sci. Process. 1999, 69 (2), 131– 147,  DOI: 10.1007/s003390050984
    Google Scholar
    43
    Electronic properties of Cu(In,Ga)Se2 heterojunction solar cells. Recent achievements, current understanding, and future challenges
    Rau, Uwe; Schock, H. W.
    Applied Physics A: Materials Science & Processing (1999), 69 (2), 131-147CODEN: APAMFC; ISSN:0947-8396. (Springer-Verlag)
    The recent achievements of high-efficiency Cu(In,Ga)Se2 heterojunction solar cells are reviewed with 187 refs. with a special focus on the understanding of the electronic transport properties of the devices. Th authors discuss the basic limitations of the device performance, the present understanding of electronic device anal., as well as the role of intrinsic defects and of the interfaces for the performance of the solar cells.
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  44. 44
    Wang, R.; Wang, Y.; Pan, Y.; Qin, D.; Weng, G.; Hu, X.; Tao, J.; Luo, X.; Chen, S.; Zhu, Z.; Chu, J.; Akiyama, H. Improving the Performance of Sb2S3 Thin-Film Solar Cells by Optimization of VTD Source-Substrate Proximity. Sol. Energy 2021, 220, 942– 948,  DOI: 10.1016/j.solener.2021.03.052
    Google Scholar
    44
    Improving the performance of Sb2S3 thin-film solar cells by optimization of VTD source-substrate proximity
    Wang, Rui; Wang, Youyang; Pan, Yanlin; Qin, Deyang; Weng, Guoen; Hu, Xiaobo; Tao, Jiahua; Luo, Xianjia; Chen, Shaoqiang; Zhu, Ziqiang; Chu, Junhao; Akiyama, Hidefumi
    Solar Energy (2021), 220 (), 942-948CODEN: SRENA4; ISSN:0038-092X. (Elsevier Ltd.)
    In this paper, Sb2S3 thin-film solar cells are fabricated by the vapor transport deposition (VTD) method. The effect of the source-substrate proximity on the performance of Sb2S3 thin-film solar cells has been investigated and comparative studies of different source-substrate proximity are carried out. The device efficiency is improved from 0.83 to 3.02% by optimizing the source-substrate proximity with the augment of open-circuit voltage, short-circuit c.d. and fill factor. X-ray diffraction and SEM studies indicate that the deposited Sb2S3 films can achieve optimal grain orientation, high crystallinity, and compact morphol. Moreover, the current transport mechanism is analyzed in detail from dark c.d.-voltage (J-V) measurements and shows the optimal sample to be least affected by Shockley-Read-Hall recombination and space-charge-limited current (SCLC). Meanwhile, temp. and light intensity-dependent open-circuit voltage measurements reveal the carrier recombination rates are lowest for the optimal cell in all regions, including the CdS/Sb2S3 interface, the space-charge region (SCR), and the quasi-neutral region (QNR). These can account for the efficiency enhancement of the optimal cell and can be used to facilitate the further development of Sb2S3 thin-film solar cells.
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  45. 45
    Hu, X.; Tao, J.; Wang, R.; Wang, Y.; Pan, Y.; Weng, G.; Luo, X.; Chen, S.; Zhu, Z.; Chu, J.; Akiyama, H. Fabricating over 7%-Efficient Sb2(S,Se)3 Thin-Film Solar Cells by Vapor Transport Deposition Using Sb2Se3 and Sb2S3 Mixed Powders as the Evaporation Source. J. Power Sources 2021, 493, 229737  DOI: 10.1016/j.jpowsour.2021.229737
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    45
    Fabricating over 7%-efficient Sb2(S,Se)3 thin-film solar cells by vapor transport deposition using Sb2Se3 and Sb2S3 mixed powders as the evaporation source
    Hu, Xiaobo; Tao, Jiahua; Wang, Rui; Wang, Youyang; Pan, Yanlin; Weng, Guoen; Luo, Xianjia; Chen, Shaoqiang; Zhu, Ziqiang; Chu, Junhao; Akiyama, Hidefumi
    Journal of Power Sources (2021), 493 (), 229737CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
    In this study, Sb2(S,Se)3 thin films are fabricated using the vapor transport deposition (VTD) method, with Sb2Se3 and Sb2S3 mixed powders as the evapn. source. The performance of the corresponding glass/ITO/CdS/Sb2(S,Se)3/Au solar cells are found to be correlated to the mass ratio between Sb2S3 and the overall powder mixt. The properties of the Sb2(S,Se)3 thin films and cell devices adopting four different Sb2S3 mass ratios (x = 0.1, 0.25, 0.5 and 0.75) are compared. Further, the elec. properties - from dark and light J-V measurements; structural properties - from X-ray diffraction and scanning electron microscope measurements; and carrier-recombination rates at the buffer/absorber interface in the space-charge region (SCR) and in the quasi-neutral region - from temp.-illumination-dependent open-circuit voltage (VOC) measurements - are compared. It is found that a Sb2(S,Se)3 solar cell with a Sb2S3 mass ratio of 0.25 had optimal crystallinity, the lowest d. of deep traps and the smallest carrier-recombination rates at the interface, leading to a high efficiency of 7.31%.
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  46. 46
    Kauk-Kuusik, M.; Timmo, K.; Muska, K.; Pilvet, M.; Krustok, J.; Danilson, M.; Mikli, V.; Josepson, R.; Grossberg-Kuusk, M. Reduced Recombination through CZTS/CdS Interface Engineering in Monograin Layer Solar Cells. J. Phys.: Energy 2022, 4 (2), 024007  DOI: 10.1088/2515-7655/ac618d
    Google Scholar
    There is no corresponding record for this reference.
  47. 47
    Lee, S. W.; Keum, H.-S.; Kim, H. S.; Kim, H. J.; Ahn, K.; Lee, D. R.; Kim, J. H.; Lee, H. H. Temperature-Dependent Evolution of Poly(3-Hexylthiophene) Type-II Phase in a Blended Thin Film. Macromol. Rapid Commun. 2016, 37 (3), 203– 208,  DOI: 10.1002/marc.201500527
    Google Scholar
    47
    Temperature-Dependent Evolution of Poly(3-Hexylthiophene) Type-II Phase in a Blended Thin Film
    Lee, Si Woo; Keum, Hee-Sung; Kim, Han Seong; Kim, Hyo Jung; Ahn, Kwangseok; Lee, Dong Ryeol; Kim, Je Han; Lee, Hyun Hwi
    Macromolecular Rapid Communications (2016), 37 (3), 203-208CODEN: MRCOE3; ISSN:1022-1336. (Wiley-VCH Verlag GmbH & Co. KGaA)
    The structure of P3HT in P3HT:PCBM films is examd. on a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) substrate subjected to cryo-cooling to low temp. (-143 °C) followed by gradual heating to 50 °C. The behavior of these systems is examd. in the absence and presence of an Al electrode on top of the P3HT:PCBM film. At temps. below -10 °C, only the type-I phase of P3HT is obsd. However, the type-II phase of P3HT starts to form near -10 °C, in both the presence and absence of the Al layer. In the system without an Al layer, the type-II phase disappears at 30 °C, but this phase persists to 50 °C in the presence of the Al layer. Concomitant with the formation of the type-II phase, a 1:3 ordered P3HT type-II (1/3,0,0) superlattice peak emerged. The type-II domains tend to form near the Al electrode layer and show a higher degree of alignment than the type-I crystals.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvFent7jM&md5=62503d2e6e4187ad7936a11c7995565c
  48. 48
    Grigas, J.; Karpus, A. Dielectric Properties of Sb2S3 Crystals. Phys. Solid State 1967, 9, 2882– 2886
    Google Scholar
    There is no corresponding record for this reference.
  49. 49
    Nadenau, V.; Rau, U.; Jasenek, A.; Schock, H. W. Electronic Properties of CuGaSe2-Based Heterojunction Solar Cells. Part I. Transport Analysis. J. Appl. Phys. (Melville, NY, U. S.) 2000, 87 (1), 584– 593,  DOI: 10.1063/1.371903
    Google Scholar
    There is no corresponding record for this reference.
  50. 50
    Beck, H. E.; Zimmermann, N. E.; McVicar, T. R.; Vergopolan, N.; Berg, A.; Wood, E. F. Present and Future Köppen-Geiger Climate Classification Maps at 1-Km Resolution. Sci. Data 2018, 5 (1), 180214  DOI: 10.1038/sdata.2018.214
    Google Scholar
    50
    Present and future Koppen-Geiger climate classification maps at 1-km resolution
    Beck Hylke E; Vergopolan Noemi; Berg Alexis; Wood Eric F; Zimmermann Niklaus E; Zimmermann Niklaus E; McVicar Tim R; McVicar Tim R
    Scientific data (2018), 5 (), 180214 ISSN:.
    We present new global maps of the Koppen-Geiger climate classification at an unprecedented 1-km resolution for the present-day (1980-2016) and for projected future conditions (2071-2100) under climate change. The present-day map is derived from an ensemble of four high-resolution, topographically-corrected climatic maps. The future map is derived from an ensemble of 32 climate model projections (scenario RCP8.5), by superimposing the projected climate change anomaly on the baseline high-resolution climatic maps. For both time periods we calculate confidence levels from the ensemble spread, providing valuable indications of the reliability of the classifications. The new maps exhibit a higher classification accuracy and substantially more detail than previous maps, particularly in regions with sharp spatial or elevation gradients. We anticipate the new maps will be useful for numerous applications, including species and vegetation distribution modeling. The new maps including the associated confidence maps are freely available via www.gloh2o.org/koppen.
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  51. 51
    Artegiani, E.; Major, J. D.; Shiel, H.; Dhanak, V.; Ferrari, C.; Romeo, A. How the Amount of Copper Influences the Formation and Stability of Defects in CdTe Solar Cells. Sol. Energy Mater. Sol. Cells 2020, 204, 110228  DOI: 10.1016/j.solmat.2019.110228
    Google Scholar
    51
    How the amount of copper influences the formation and stability of defects in CdTe solar cells
    Artegiani, Elisa; Major, Jonathan D.; Shiel, Huw; Dhanak, Vin; Ferrari, Claudio; Romeo, Alessandro
    Solar Energy Materials & Solar Cells (2020), 204 (), 110228CODEN: SEMCEQ; ISSN:0927-0248. (Elsevier B.V.)
    With a 22.1% efficiency record and the successful results in terms of prodn. yield, CdTe based thin film solar cells are today a competing technol. with traditional silicon solar cells. Despite different copper-free back contacts have been applied, Cu is present in all the most performing CdTe devices. On the other hand, it is well known that Cu is a fast diffuser in CdTe, and it heavily influences the devices degrdn.; thus controlling its concn. is very important. In this paper a study of the influence of copper quantity on the performance of the devices and stability at the back contact is presented. CdTe cells fabricated with a 0.1 nm thick Cu layer are compared to devices fabricated with 2.0, 1.0 and 0.5 nm thick Cu layers. The amt. of copper affects the performance and aging of the samples. Moreover an inversion of the bias dependency (solar cells in open circuit or in short circuit under current flow), during the aging, occurs in samples contg. a copper layer below a certain thickness, suggesting that another degrdn. mechanism predominates.
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  52. 52
    Thompson, C. V. Solid-State Dewetting of Thin Films. Annu. Rev. Mater. Res. 2012, 42 (1), 399– 434,  DOI: 10.1146/annurev-matsci-070511-155048
    Google Scholar
    52
    Solid-state dewetting of thin films
    Thompson, Carl V.
    Annual Review of Materials Research (2012), 42 (), 399-434CODEN: ARMRCU; ISSN:1531-7331. (Annual Reviews Inc.)
    A review. Solid films are usually metastable or unstable in the as-deposited state, and they will dewet or agglomerate to form islands when heated to sufficiently high temps. This process is driven by surface energy minimization and can occur via surface diffusion well below a film's melting temp., esp. when the film is very thin. Dewetting during processing of films for use in micro- and nanosystems is often undesirable, and means of avoiding dewetting are important in this context. However, dewetting can also be useful in making arrays of nanoscale particles for electronic and photonic devices and for catalyzing growth of nanotubes and nanowires. Templating of dewetting using patterned surface topog. or prepatterning of films can be used to create ordered arrays of particles and complex patterns of partially dewetted structures. Studies of dewetting can also provide fundamental new insight into the effects of surface energy anisotropy and facets on shape evolution.
    >> More from SciFinder ®
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  53. 53
    Itzhaik, Y.; Niitsoo, O.; Page, M.; Hodes, G. Sb2S3-Sensitized Nanoporous TiO2 Solar Cells. J. Phys. Chem. C 2009, 113 (11), 4254– 4256,  DOI: 10.1021/jp900302b
    Google Scholar
    53
    Sb2S3-Sensitized Nanoporous TiO2 Solar Cells
    Itzhaik, Yafit; Niitsoo, Olivia; Page, Miles; Hodes, Gary
    Journal of Physical Chemistry C (2009), 113 (11), 4254-4256CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
    Extremely Thin Absorber (ETA) solar cells were made using chem.-bath-deposited Sb2S3 as the absorber and TiO2/CuSCN as the interpenetrating electron/hole conductors. A solar conversion efficiency of 3.37% at 1 sun illumination was obtained. Surface oxidn. of the Sb2S3 formed a passivation layer on Sb2S3 - without this oxidn. much poorer cells were obtained. Preliminary measurements showed good stability over 3 days of illumination (at 60 mW/cm2) under load.
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  • Abstract

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    Figure 1

    Figure 1. Top-down and cross-sectional SEM images of heat-treated Sb2S3 absorbers (in yellow) grown onto an FTO (in cyan)/TiO2 (in dark blue) substrate at deposition temperatures of (a, d) 200 °C, (b, e) 230 °C, and (c, f) 260 °C.

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    Figure 2

    Figure 2. (a) XRD patterns, (b) Raman spectra, and (c) absorption spectra of heat-treated Sb2S3 absorbers grown at 200, 230, and 260 °C, TU/SbEX 3.0. (d) X-ray photoelectron spectroscopy (XPS) survey spectrum, XPS results of (e) C 1s region, (f) Sb 3d and O 1s regions, and (g) S 2p and Sb 4s regions, and (h) valence band (VB) onset of the heat-treated Sb2S3 absorber grown at 200 °C.

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    Figure 3

    Figure 3. (a) J–V curves of the best devices. Statistics on (b) JSC, (c) VOC, (d) efficiency, (e) fill factor, (f) RS, and (g) RSH of solar cells measured in the dark or under AM1.5G conditions as a function of Sb2S3 deposition temperature.

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    Figure 4

    Figure 4. Temperature dependent (a, c) illuminated and (b, d) dark I–V curves of solar cells based on Sb2S3 grown at (a, b) 200 and (c, d) 260 °C.

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    Figure 5

    Figure 5. Temperature dependence of (a) VOC, JSC, (b) fill factor and efficiency, (c) series resistance, (d) shunt resistance, and (e) ideality factor corrected saturation current of solar cells based on Sb2S3 grown at (a, b) 200 and (d, e) 260 °C. Numerical data are given in Tables S3–S6.

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    Figure 6

    Figure 6. Deep level transient spectroscopy (DLTS) analysis for Sb2S3 solar cells with absorber layers deposited at 200 and 260 °C showing (a) normalized ΔC values extracted from capacitance transients as a function of temperature and (b) Arrhenius determination of trap energy and capture cross section with values given in Table 2. Determined values were then used to model spectra overlaid on measurement data in Figure 6a.

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    Figure 7

    Figure 7. Top-down and cross-sectional SEM images of heat-treated Sb2S3 absorbers (in yellow) grown onto a FTO (in cyan)/TiO2 (in dark blue) substrate at a deposition temperature of 200 °C by USP from a solution with TU/SbEX molar ratios of (a, g) 0.5, (b, h) 1.0, (c, i) 1.5, (d, j) 3.0, (e, k) 4.5, and (f, l) 6.0.

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    Figure 8

    Figure 8. (a) X-ray diffraction (XRD) patterns, (b) Raman spectra, (c) cumulative XRD texture coefficients, (d) absorption spectra, X-ray photoelectron spectroscopy (XPS) results of (e) S 2p region and (f) intensity contributions, extrapolated to TU/SbEX 0, and XPS results of (g) Sb 3d and (h) Sb 4d region, and (i) intensity contributions, extrapolated to TU/SbEX 0, of heat-treated Sb2S3 absorbers grown onto glass/FTO/TiO2 from a solution with variable molar ratios of TU/SbEX.

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    Figure 9

    Figure 9. (a) J–V curves and (b) EQE and integrated JSC of best devices based on Sb2S3 films grown with a variable molar ratio of TU/SbEX. (c) SEM cross-section of the best device. ( Statistics on (d) JSC, (e) VOC, (f) efficiency, (g) fill factor, (h) series resistance, and (i) shunt resistance. Band diagram of the solar cell layer structure at (j) TU/SbEX 3.0 and (k) 4.5.

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  • References

    This article references 53 other publications.

    1. 1
      Solar Energy; Richter, C., Lincot, D., Gueymard, C. A., Eds.; Springer: 2012; pp 170– 173.
      There is no corresponding record for this reference.
    2. 2
      Greenwood, N. N.; Earnshaw, A. Arsenic, Antimony and Bismuth. In Chemistry of the Elements, 2nd ed.; Butterworth-Heinemann: 1997; pp 581– 582.
      There is no corresponding record for this reference.
    3. 3
      U.S. Geological Survey. Mineral Commodity Summaries 2022; U.S. Geological Survey: 2022; p 202.  DOI: 10.3133/mcs2022 .
      There is no corresponding record for this reference.
    4. 4
      Dong, J.; Liu, Y.; Wang, Z.; Zhang, Y. Boosting VOC of Antimony Chalcogenide Solar Cells: A Review on Interfaces and Defects. Nano Select 2021, 2 (10), 1818– 1848,  DOI: 10.1002/nano.202000288
      4
      Boosting VOC of antimony chalcogenide solar cells: A review on interfaces and defects
      Dong, Jiabin; Liu, Yue; Wang, Zuoyun; Zhang, Yi
      Nano Select (2021), 2 (10), 1818-1848CODEN: NSAECD; ISSN:2688-4011. (Wiley-VCH Verlag GmbH & Co. KGaA)
      A review. Antimony chalcogenides, including Sb2S3, Sb2Se3, and Sb2(S, Se)3, have been developed as attractive non-toxic and earth-abundant solar absorber candidates among the thin-film photovoltaic devices. Presently, a record certified power conversion efficiency of 10.5% has been demonstrated for antimony chalcogenide solar cells, which is significantly lower than that of Cu2(In, Ga)Se2 (23.35%) and CdTe (22.1%) thin-film solar cells. The inferior performance in antimony chalcogenide solar cells is mainly owing to a large open-circuit voltage (VOC) deficit resulted from the defect and interface-assisted recombination. Herein, a comprehensive review on the recent advancements interface band alignment and defect passivation are carried out. This review will provide a solid understanding on the interfaces and defects of antimony chalcogenide solar cells, which is beneficial to the research and development of such kind of solar cells.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xlt1Onur0%253D&md5=3dbd9dd928045a428497c33711e907d2
    5. 5
      Gutiérrez, Y.; Ovvyan, A. P.; Santos, G.; Juan, D.; Rosales, S. A.; Junquera, J.; García-Fernández, P.; Dicorato, S.; Giangregorio, M. M.; Dilonardo, E.; Palumbo, F.; Modreanu, M.; Resl, J.; Ishchenko, O.; Garry, G.; Jonuzi, T.; Georghe, M.; Cobianu, C.; Hingerl, K.; Cobet, C.; Moreno, F.; Pernice, W. H. P.; Losurdo, M. Interlaboratory Study on Sb2S3 Interplay between Structure, Dielectric Function, and Amorphous-to-Crystalline Phase Change for Photonics. iScience 2022, 25 (6), 104377,  DOI: 10.1016/j.isci.2022.104377
      5
      Interlaboratory study on Sb2S3 interplay between structure, dielectric function, and amorphous-to-crystalline phase change for photonics
      Gutierrez, Yael; Ovvyan, Anna P.; Santos, Gonzalo; Juan, Dilson; Rosales, Saul A.; Junquera, Javier; Garcia-Fernandez, Pablo; Dicorato, Stefano; Giangregorio, Maria M.; Dilonardo, Elena; Palumbo, Fabio; Modreanu, Mircea; Resl, Josef; Ishchenko, Olga; Garry, Guy; Jonuzi, Tigers; Georghe, Marin; Cobianu, Cornel; Hingerl, Kurt; Cobet, Christoph; Moreno, Fernando; Pernice, Wolfram H. P.; Losurdo, Maria
      iScience (2022), 25 (6), 104377CODEN: ISCICE; ISSN:2589-0042. (Elsevier B.V.)
      Antimony sulfide, Sb2S3, is interesting as the phase-change material for applications requiring high transmission from the visible to telecom wavelengths, with its band gap tunable from 2.2 to 1.6 eV, depending on the amorphous and cryst. phase. Here we present results from an interlab. study on the interplay between the structural change and resulting optical contrast during the amorphous-to-cryst. transformation triggered both thermally and optically. By statistical anal. of Raman and ellipsometric spectroscopic data, we have identified two regimes of crystn., namely 250°C ≤ T < 300°C, resulting in Type-I spherulitic crystn. yielding an optical contrast Δn ∼ 0.4, and 300 ≤ T < 350°C, yielding Type-II crystn. bended spherulitic structure with different dielec. function and optical contrast Δn ∼ 0.2 below 1.5 eV. Based on our findings, applications of on-chip reconfigurable nanophotonic phase modulators and of a reconfigurable high-refractive-index core/phase-change shell nanoantenna are designed and proposed.
      >> More from SciFinder ®
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    6. 6
      Büttner, P.; Scheler, F.; Döhler, D.; Barr, M. K. S.; Bosch, M.; Rey, M.; Yokosawa, T.; Hinz, S.; Maultzsch, J.; Spiecker, E.; Vogel, N.; Mínguez-Bacho, I.; Bachmann, J. Continuous, Crystalline Sb2S3 Ultrathin Light Absorber Coatings in Solar Cells Based on Photonic Concentric p-i-n Heterojunctions. Nano Energy 2022, 103, 107820  DOI: 10.1016/j.nanoen.2022.107820
      6
      Continuous, crystalline Sb2S3 ultrathin light absorber coatings in solar cells based on photonic concentric p-i-n heterojunctions
      Buettner, Pascal; Scheler, Florian; Doehler, Dirk; Barr, Maissa K. S.; Bosch, Michael; Rey, Marcel; Yokosawa, Tadahiro; Hinz, Sandra; Maultzsch, Janina; Spiecker, Erdmann; Vogel, Nicolas; Minguez-Bacho, Ignacio; Bachmann, Julien
      Nano Energy (2022), 103 (Part_B), 107820CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)
      Many modern types of solar cells that rely exclusively on earth-abundant non-toxic materials include interfaces between a heavier metal chalcogenide and another type of semiconductor. Often, the chem. (adhesion) and phys. (charge transfer) characteristics of those interfaces are the defining factors for the final device performance. Here, we describe that a ZnS adhesion layer is not sufficient to prevent the dewetting of Sb2S3 upon annealing a thin layer of it on an oxidic surface if the substrate is not planar and features highly curved surfaces. An ALD-coated sacrificial capping layer of ZnO prevents the morphol. rearrangements of Sb2S3 during thermal crystn. and can be removed subsequently. When implemented towards a photovoltaic p-i-n heterojunction, this strategy furnishes perfect conformality of the layer stack but unsatisfactory performance. The correlation of interface chem. with the elec. properties and the device performance identifies a reducing effect of ZnO at. layer deposition chem. on the Sb2S3 surface as the cause of Zn diffusion into the light absorbing semiconductor. This deleterious doping can be prevented by a preliminary oxidative treatment of the Sb2S3 surface with ozone. When applied to a structured substrate consisting of ordered arrays of nanospheres, this approach yields the first ever concentric p-i-n heterojunction solar cells with photonic light trapping effect-a geometry which in comparison with std. scattering layers on top inherently generates a very large refractive index contrast. In the red part of the visible spectrum, light absorption amts. to the value expected with four passes through a planar layer of the thickness used here (35 nm Sb2S3). This effect allows us to demonstrate > 5% overall solar energy conversion efficiency with only 35 nm of a simple light absorber phase that uses no toxic, rare materials.
      >> More from SciFinder ®
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    7. 7
      Thorneycroft, W. E. Antimony and Sulphur. In Antimony and Bismuth; Friend, J. N., Ed.; ; Charles Griffin: 1936; A Text Book of Inorganic Chemistry, Vol. VI, Part V, pp 97– 101.
      There is no corresponding record for this reference.
    8. 8
      Kim, D.-H.; Lee, S.-J.; Park, M. S.; Kang, J.-K.; Heo, J. H.; Im, S. H.; Sung, S.-J. Highly Reproducible Planar Sb2S3-Sensitized Solar Cells Based on Atomic Layer Deposition. Nanoscale 2014, 6 (23), 14549– 14554,  DOI: 10.1039/C4NR04148H
      8
      Highly reproducible planar Sb2S3-sensitized solar cells based on atomic layer deposition
      Kim, Dae-Hwan; Lee, Sang-Ju; Park, Mi Sun; Kang, Jin-Kyu; Heo, Jin Hyuck; Im, Sang Hyuk; Sung, Shi-Joon
      Nanoscale (2014), 6 (23), 14549-14554CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
      A high-quality Sb2S3 thin-absorber with controllable thickness was reproducibly formed by at. layer deposition (ALD) technique. Compared with conventional chem. bath deposition (CBD), the Sb2S3 absorber deposited by ALD did not contain oxide or oxygen impurities and showed a very uniform thickness of Sb2S3 absorbers formed on a rough surface of dense blocking TiO2/F-doped SnO2 (bl-TiO2/FTO) substrate. The planar ALD-Sb2S3 solar cells comprised of Au/Poly-3-hexylthiophene/ALD-Sb2S3/bl-TiO2/FTO showed significantly improved power conversion efficiency of 5.77% at 1 sun condition and narrow efficiency deviation, whereas the planar CBD-Sb2S3 solar cells exhibited 2.17% power conversion efficiency. The high efficiency and good reproducibility of ALD-Sb2S3 solar cell devices is attributed to reduced backward recombination because of the inhibition of oxide defects within ALD-Sb2S3 absorber and the conformal deposition of very uniform Sb2S3 absorbers on the blocking TiO2 surface by ALD process.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslaqsrnE&md5=322b872b7a85370a52e8e51cb8b30528
    9. 9
      Wang, S.; Zhao, Y.; Che, B.; Li, C.; Chen, X.; Tang, R.; Gong, J.; Wang, X.; Chen, G.; Chen, T.; Li, J.; Xiao, X. A Novel Multi-Sulfur Source Collaborative Chemical Bath Deposition Technology Enables 8%-Efficiency Sb2S3 Planar Solar Cells. Adv. Mater. 2022, 34 (41), 2206242  DOI: 10.1002/adma.202206242
      9
      A Novel Multi-Sulfur Source Collaborative Chemical Bath Deposition Technology Enables 8%-Efficiency Sb2S3 Planar Solar Cells
      Wang, Shaoying; Zhao, Yuqi; Che, Bo; Li, Chuang; Chen, Xueling; Tang, Rongfeng; Gong, Junbo; Wang, Xiaomin; Chen, Guilin; Chen, Tao; Li, Jianmin; Xiao, Xudong
      Advanced Materials (Weinheim, Germany) (2022), 34 (41), 2206242CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Sb2S3 as a light-harvesting material has attracted great attention for applications in both single-junction and tandem solar cells. Such solar cell has been faced with current challenge of low power conversion efficiency (PCE), which has stagnated for 8 years. It has been recognized that the synthesis of high-quality absorber film plays a crit. role in efficiency improvement. Here, using fresh precursor materials for antimony (antimony potassium tartrate) and combined sulfur (sodium thiosulfate and thioacetamide), a unique chem. bath deposition procedure is created. Due to the complexation of sodium thiosulfate and the advantageous hydrolysis cooperation between these two sulfur sources, the heterogeneous nucleation and the S2- releasing processes are boosted. As a result, there are noticeable improvements in the deposition rate, film morphol., crystallinity, and preferred orientations. Addnl., the improved film quality efficiently lowers charge trapping capacity, suppresses carrier recombination, and prolongs carrier lifetimes, leading to significantly improved photoelec. properties. Ultimately, the PCE exceeds 8% for the first time since 2014, representing the highest efficiency in all kinds of Sb2S3 solar cells to date. This study is expected to shed new light on the fabrication of high-quality Sb2S3 film and further efficiency improvement in Sb2S3 solar cells.
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    10. 10
      Yang, Z.; Wang, X.; Chen, Y.; Zheng, Z.; Chen, Z.; Xu, W.; Liu, W.; Yang, Y.; Zhao, J.; Chen, T.; Zhu, H. Ultrafast Self-Trapping of Photoexcited Carriers Sets the Upper Limit on Antimony Trisulfide Photovoltaic Devices. Nat. Commun. 2019, 10 (1), 4540,  DOI: 10.1038/s41467-019-12445-6
      10
      Ultrafast self-trapping of photoexcited carriers sets the upper limit on antimony trisulfide photovoltaic devices
      Yang Zhaoliang; Chen Yuzhong; Chen Zeng; Zhu Haiming; Wang Xiaomin; Chen Tao; Zheng Zhenfa; Zhao Jin; Xu Wenqi; Liu Weimin; Yang Yang Michael; Zhu Haiming
      Nature communications (2019), 10 (1), 4540 ISSN:.
      Antimony trisulfide (Sb2S3) is considered to be a promising photovoltaic material; however, the performance is yet to be satisfactory. Poor power conversion efficiency and large open circuit voltage loss have been usually ascribed to interface and bulk extrinsic defects By performing a spectroscopy study on Sb2S3 polycrystalline films and single crystal, we show commonly existed characteristics including redshifted photoluminescence with 0.6 eV Stokes shift, and a few picosecond carrier trapping without saturation at carrier density as high as approximately 10(20) cm(-3). These features, together with polarized trap emission from Sb2S3 single crystal, strongly suggest that photoexcited carriers in Sb2S3 are intrinsically self-trapped by lattice deformation, instead of by extrinsic defects. The proposed self-trapping explains spectroscopic results and rationalizes the large open circuit voltage loss and near-unity carrier collection efficiency in Sb2S3 thin film solar cells. Self-trapping sets the upper limit on maximum open circuit voltage (approximately 0.8 V) and thus power conversion efficiency (approximately 16 %) for Sb2S3 solar cells.
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    11. 11
      Tang, R.; Wang, X.; Jiang, C.; Li, S.; Liu, W.; Ju, H.; Yang, S.; Zhu, C.; Chen, T. N-Type Doping of Sb2S3 Light-Harvesting Films Enabling High-Efficiency Planar Heterojunction Solar Cells. ACS Appl. Mater. Interfaces 2018, 10 (36), 30314– 30321,  DOI: 10.1021/acsami.8b08965
      11
      n-Type Doping of Sb2S3 Light-Harvesting Films Enabling High-Efficiency Planar Heterojunction Solar Cells
      Tang, Rongfeng; Wang, Xiaomin; Jiang, Chenhui; Li, Shiang; Liu, Weifeng; Ju, Huanxin; Yang, Shangfeng; Zhu, Changfei; Chen, Tao
      ACS Applied Materials & Interfaces (2018), 10 (36), 30314-30321CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
      Sb2S3 is a kind of new light-absorbing material possessing high stability in ambient environment, high absorption coeff. in the visible range, and abundant elemental storage. To improve the power conversion efficiency of Sb2S3-based solar cells, here the authors control the defect in Sb2S3 absorber films. The increase of S vacancy is able to upgrade photovoltaic properties. With the increase in S vacancy, the carrier concns. are increased. This n-type doping gives rise to an upshift of the Fermi level of Sb2S3 so that the charge transport from Sb2S3 to the electron selection material becomes dynamically favorable. The introduction of ZnCl2 in film fabrication is also found to regulate the film growth for enhanced crystallinity. Finally, the photovoltaic parameters, short-circuit c.d., open-circuit voltage, and the fill factor of the device based on the Sb2S3 film are all considerably enhanced, boosting the final power conversion efficiency from 5.15 to 6.35%. This efficiency is the highest value in planar heterojunction Sb2S3 solar cells and among the top values in all kinds of Sb2S3 solar cells. This research provides a fundamental understanding regarding the properties of Sb2S3 and a convenient approach for enhancing the performance of Sb2S3 solar cells.
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    12. 12
      Jiang, C.; Tang, R.; Wang, X.; Ju, H.; Chen, G.; Chen, T. Alkali Metals Doping for High-Performance Planar Heterojunction Sb2S3 Solar Cells. Solar RRL 2019, 3 (1), 1800272  DOI: 10.1002/solr.201800272
      There is no corresponding record for this reference.
    13. 13
      Büttner, P.; Scheler, F.; Pointer, C.; Döhler, D.; Barr, M. K. S.; Koroleva, A.; Pankin, D.; Hatada, R.; Flege, S.; Manshina, A.; Young, E. R.; Mínguez-Bacho, I.; Bachmann, J. Adjusting Interfacial Chemistry and Electronic Properties of Photovoltaics Based on a Highly Pure Sb2S3 Absorber by Atomic Layer Deposition. ACS Appl. Energy Mater. 2019, 2 (12), 8747– 8756,  DOI: 10.1021/acsaem.9b01721
      13
      Adjusting Interfacial Chemistry and Electronic Properties of Photovoltaics Based on a Highly Pure Sb2S3 Absorber by Atomic Layer Deposition
      Buettner, Pascal; Scheler, Florian; Pointer, Craig; Doehler, Dirk; Barr, Maissa K. S.; Koroleva, Aleksandra; Pankin, Dmitrii; Hatada, Ruriko; Flege, Stefan; Manshina, Alina; Young, Elizabeth R.; Minguez-Bacho, Ignacio; Bachmann, Julien
      ACS Applied Energy Materials (2019), 2 (12), 8747-8756CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)
      The combination of oxide and heavier chalcogenide layers in thin film photovoltaics suffers limitations assocd. with oxygen incorporation and sulfur deficiency in the chalcogenide layer or with a chem. incompatibility which results in dewetting issues and defect states at the interface. Here, we establish at. layer deposition (ALD) as a tool to overcome these limitations. ALD allows one to obtain highly pure Sb2S3 light absorber layers, and we exploit this technique to generate an addnl. interfacial layer consisting of 1.5 nm ZnS. This ultrathin layer simultaneously resolves dewetting and passivates defect states at the interface. We demonstrate via transient absorption spectroscopy that interfacial electron recombination is one order of magnitude slower at the ZnS-engineered interface than hole recombination at the Sb2S3/P3HT interface. The comparison of solar cells with and without oxide incorporation in Sb2S3, with and without the ultrathin ZnS interlayer, and with systematically varied Sb2S3 thickness provides a complete picture of the phys. processes at work in the devices.
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    14. 14
      Guo, L.; Zhang, B.; Li, S.; Zhang, Q.; Buettner, M.; Li, L.; Qian, X.; Yan, F. Scalable and Efficient Sb2S3 Thin-Film Solar Cells Fabricated by Close Space Sublimation. APL Materials 2019, 7 (4), 041105  DOI: 10.1063/1.5090773
      14
      Scalable and efficient Antimony sulfide thin-film solar cells fabricated by close space sublimation
      Guo, Liping; Zhang, Baiyu; Li, Shan; Zhang, Qian; Buettner, Michael; Li, Lin; Qian, Xiaofeng; Yan, Feng
      APL Materials (2019), 7 (4), 041105/1-041105/6CODEN: AMPADS; ISSN:2166-532X. (American Institute of Physics)
      Antimony sulfide as a cost-effective, low-toxic, and earth-abundant solar cell absorber with the desired bandgap was successfully deposited using a scalable close space sublimation technique. The deposition process can sep. control the substrate and source temp. with better engineering of the absorber quality. The device performance can reach 3.8% with the configuration of glass/FTO/CdS/Sb2S3/graphite back contact. The defect formation energy and the corresponding transition levels were investigated in detail using theor. calcns. Our results suggest that Sb2S3 exhibits intrinsic p-type owing to S-on-Sb antisites (SSb) and the device performance is limited by the S vacancies. The localized conduction characterization at nanoscale shows that the non-cubic Sb2S3 has conductive grains and benign grain boundaries. The study of the defects, microstructure, and nanoscale conduction behavior suggests that Sb2S3 could be a promising photovoltaic candidate for scalable manufg. (c) 2019 American Institute of Physics.
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    15. 15
      Eensalu, J. S.; Katerski, A.; Kärber, E.; Oja Acik, I.; Mere, A.; Krunks, M. Uniform Sb2S3 Optical Coatings by Chemical Spray Method. Beilstein J. Nanotechnol. 2019, 10, 198– 210,  DOI: 10.3762/bjnano.10.18
      15
      Uniform Sb2S3 optical coatings by chemical spray method
      Eensalu Jako S; Katerski Atanas; Karber Erki; Oja Acik Ilona; Mere Arvo; Krunks Malle
      Beilstein journal of nanotechnology (2019), 10 (), 198-210 ISSN:2190-4286.
      Antimony sulfide (Sb2S3), an environmentally benign material, has been prepared by various deposition methods for use as a solar absorber due to its direct band gap of ≈1.7 eV and high absorption coefficient in the visible light spectrum (1.8 × 10(5) cm(-1) at 450 nm). Rapid, scalable, economically viable and controllable in-air growth of continuous, uniform, polycrystalline Sb2S3 absorber layers has not yet been accomplished. This could be achieved with chemical spray pyrolysis, a robust chemical method for deposition of thin films. We applied a two-stage process to produce continuous Sb2S3 optical coatings with uniform thickness. First, amorphous Sb2S3 layers, likely forming by 3D Volmer-Weber island growth through a molten phase reaction between SbCl3 and SC(NH2)2, were deposited in air on a glass/ITO/TiO2 substrate by ultrasonic spraying of methanolic Sb/S 1:3 molar ratio solution at 200-210 °C. Second, we produced polycrystalline uniform films of Sb2S3 (Eg 1.8 eV) with a post-deposition thermal treatment of amorphous Sb2S3 layers in vacuum at 170 °C, <4 × 10(-6) Torr for 5 minutes. The effects of the deposition temperature, the precursor molar ratio and the thermal treatment temperature on the Sb2S3 layers were investigated using Raman spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and UV-vis-NIR spectroscopy. We demonstrated that Sb2S3 optical coatings with controllable structure, morphology and optical properties can be deposited by ultrasonic spray pyrolysis in air by tuning of the deposition temperature, the Sb/S precursor molar ratio in the spray solution, and the post-deposition treatment temperature.
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    16. 16
      Choi, Y. C.; Lee, D. U.; Noh, J. H.; Kim, E. K.; Seok, S. I. Highly Improved Sb2S3 Sensitized-Inorganic–Organic Heterojunction Solar Cells and Quantification of Traps by Deep-Level Transient Spectroscopy. Adv. Funct. Mater. 2014, 24 (23), 3587– 3592,  DOI: 10.1002/adfm.201304238
      16
      Highly Improved Sb2S3 Sensitized-Inorganic-Organic Heterojunction Solar Cells and Quantification of Traps by Deep-Level Transient Spectroscopy
      Choi, Yong Chan; Lee, Dong Uk; Noh, Jun Hong; Kim, Eun Kyu; Seok, Sang Il
      Advanced Functional Materials (2014), 24 (23), 3587-3592CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
      The light-harvesting Sb2S3 surface on mesoporous-TiO2 in inorg.-org. heterojunction solar cells is sulfurized with thioacetamide (TA). The photovoltaic performances are compared before and after TA treatment, and the state of the Sb2S3 is studied by x-ray diffraction, XPS, and deep-level transient spectroscopy (DLTS). Although there are no differences in crystallinity and compn., the TA-treated solar cells exhibit significantly enhanced performance compared to pristine Sb2S3-sensitized solar cells. From DLTS anal., the performance enhancement is mainly attributed to the extinction of trap sites, which are present at a d. of (2-5) × 1014 cm-3 in Sb2S3, by TA treatment. Through such a simple treatment, the cell records an overall power conversion efficiency (PCE) of 7.5% through a metal mask under simulated illumination (AM 1.5 G, 100 mW cm-2) with a very high open circuit voltage of 711.0 mV. This PCE is, thus far, the highest reported for fully solid-state chalcogenide-sensitized solar cells.
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    17. 17
      European Commission. Communication from the Commission to the European Parliament, The Council, The European Economic and Social Committee and the Committee of the regions Critical Raw Materials Resilience: Charting a Path towards Greater Security and Sustainability, 2020. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52020DC0474.
      There is no corresponding record for this reference.
    18. 18
      Department of the Interior; Office of the Secretary. Final List of Critical Minerals 2018, 2018. https://www.federalregister.gov/documents/2018/05/18/2018-10667/final-list-of-critical-minerals-2018.
      There is no corresponding record for this reference.
    19. 19
      2022 Critical Minerals Strategy, 2022. https://www.industry.gov.au/publications/critical-minerals-strategy-2022.
      There is no corresponding record for this reference.
    20. 20
      Lee, S.-J.; Sung, S.-J.; Yang, K.-J.; Kang, J.-K.; Kim, J. Y.; Do, Y. S.; Kim, D.-H. Approach to Transparent Photovoltaics Based on Wide Band Gap Sb2S3 Absorber Layers and Optics-Based Device Optimization. ACS Appl. Energy Mater. 2020, 3 (12), 12644– 12651,  DOI: 10.1021/acsaem.0c02552
      20
      Approach to Transparent Photovoltaics Based on Wide Band Gap Sb2S3 Absorber Layers and Optics-Based Device Optimization
      Lee, Sang-Ju; Sung, Shi-Joon; Yang, Kee-Jeong; Kang, Jin-Kyu; Kim, Jun Yong; Do, Yun Seon; Kim, Dae-Hwan
      ACS Applied Energy Materials (2020), 3 (12), 12644-12651CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)
      Numerous methods have been employed for utilizing inorg. thin films to improve the stability of transparent photovoltaics (TPVs). However, the use of these methods was restricted due to limitations involving restricted phys. dimensions, complex fabrication processes, visible transparency, and photovoltaic performance. In this study, a novel approach to novel TPVs based on wide band gap inorg. thin-film solar cell devices was first proposed. This approach was based on an Sb2S3 thin-film absorber and the optical optimization of a planar-type solar cell device structure. High-quality and uniformly thick Sb2S3 thin films were deposited via at. layer deposition (ALD) to produce a high-quality transparent absorber layer for a planar-type transparent thin-film solar cell. To maintain the light transmittance of ALD-Sb2S3 solar cell devices, a flat indium tin oxide (ITO) substrate, a low-temp.-processed ALD TiO2 electron-transport layer (ETL), and an ultrathin Au top electrode were systematically combined with the transparent ALD-Sb2S3 absorber layer. The transparent ALD-Sb2S3 solar cell device showed a power conversion efficiency of 3.44% and an av. light transmittance of 13%. These results proposed the technol. possibility of using novel inorg. transparent Sb2S3 solar cell devices for transparent applications, such as self-powered transparent displays, high-efficiency tandem solar cells, robust bifacial solar cells, and so on.
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    21. 21
      Kumar, P.; You, S.; Vomiero, A. CuSCN as a Hole Transport Layer in an Inorganic Solution-Processed Planar Sb2S3 Solar Cell, Enabling Carbon-Based and Semitransparent Photovoltaics. J. Mater. Chem. C 2022, 10 (43), 16273– 16282,  DOI: 10.1039/D2TC03420D
      21
      CuSCN as a hole transport layer in an inorganic solution-processed planar Sb2S3 solar cell, enabling carbon-based and semitransparent photovoltaics
      Kumar, Pankaj; You, Shujie; Vomiero, Alberto
      Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2022), 10 (43), 16273-16282CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
      Sb2S3 is an emerging inorg. photovoltaic absorber material with attractive properties such as high absorption coeff., stability, earth-abundance, non-toxicity, and low-temp. soln. processability. Furthermore, with a bandgap of ca. 1.7 eV, it can also be used in semitransparent or tandem solar cell applications. Here, an inorg. wide-bandgap hole transport layer (HTL), copper thiocyanate (CuSCN), is used in an Sb2S3 solar cell employing a simple planar geometry. The compact and highly transparent CuSCN HTL was compatible with the low-cost, blade-coated carbon/Ag electrode and a semitransparent solar cell device. With Au and carbon/Ag electrodes, chem. bath deposited Sb2S3 solar cells achieved power conversion efficiencies (PCEs) of 1.75% and 1.95%, resp. At the same time, a preliminary semitransparent Sb2S3 device with an ultrathin Au (∼15 nm) electrode showed a good av. visible transmittance (AVT) of 26.7% at a PCE of 1.65%.
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    22. 22
      Han, J.; Pu, X.; Zhou, H.; Cao, Q.; Wang, S.; He, Z.; Gao, B.; Li, T.; Zhao, J.; Li, X. Synergistic Effect through the Introduction of Inorganic Zinc Halides at the Interface of TiO2 and Sb2S3 for High-Performance Sb2S3 Planar Thin-Film Solar Cells. ACS Appl. Mater. Interfaces 2020, 12 (39), 44297– 44306,  DOI: 10.1021/acsami.0c11550
      22
      Synergistic Effect through the Introduction of Inorganic Zinc Halides at the Interface of TiO2 and Sb2S3 for High-Performance Sb2S3 Planar Thin-Film Solar Cells
      Han, Jian; Pu, Xingyu; Zhou, Hui; Cao, Qi; Wang, Shuangjie; He, Ziwei; Gao, Bingyu; Li, Tongtong; Zhao, Junsong; Li, Xuanhua
      ACS Applied Materials & Interfaces (2020), 12 (39), 44297-44306CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
      The competition between charge recombination and extn. principally affects the fill factor (FF) and power conversion efficiency (PCE) of planar thin-film solar cells. In Sb2S3 thin-film solar cells, the electrocharge recombination and extn. n transport layer (ETL) plays a significant role in electron extn. and detn. of Sb2S3 film absorber quality. Herein, a TiO2 ETL is strategically modified using an inorg. salt zinc halide (i.e., ZnCl2, ZnBr2, ZnI2), which simultaneously improves the electronic properties of TiO2 and promotes the growth of Sb2S3 films with larger grain size and higher crystallinity. The exptl. results and theor. calcns. further reveal that the zinc halide can interact with TiO2 and simultaneously bond strongly with the upper Sb2S3 film, which creates a unique pathway for electron transfer, passivates the trap states, and alleviates the recombination losses effectively. As a result, an av. PCE of 6.87 ± 0.11% and the highest PCE of 7.08% have been attained with an improved FF from 51.22 to 61.61% after ZnCl2 introduction. Addnl., introduction of ZnCl2 helps the unencapsulated devices to maintain 93% of their original performance after 2400 h of storage in a nitrogen-filled glovebox. This work develops an effective route for the optimization of ETLs and defect healing using simple and low-cost inorg. salts.
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    23. 23
      Han, J.; Wang, S.; Yang, J.; Guo, S.; Cao, Q.; Tang, H.; Pu, X.; Gao, B.; Li, X. Solution-Processed Sb2S3 Planar Thin Film Solar Cells with a Conversion Efficiency of 6.9% at an Open Circuit Voltage of 0.7 V Achieved via Surface Passivation by a SbCl3 Interface Layer. ACS Appl. Mater. Interfaces 2020, 12 (4), 4970– 4979,  DOI: 10.1021/acsami.9b15148
      23
      Solution-Processed Sb2S3 Planar Thin Film Solar Cells with a Conversion Efficiency of 6.9% at an Open Circuit Voltage of 0.7 V Achieved via Surface Passivation by a SbCl3 Interface Layer
      Han, Jian; Wang, Shuangjie; Yang, Jiabao; Guo, Shaohui; Cao, Qi; Tang, Huijie; Pu, Xingyu; Gao, Bingyu; Li, Xuanhua
      ACS Applied Materials & Interfaces (2020), 12 (4), 4970-4979CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
      Interfaces in Sb2S3 thin film solar cells strongly affect their open-circuit voltage (VOC) and power conversion efficiency (PCE). Finding an effective method of reducing the defects is a promising approach for increasing the VOC and PCE. Herein, the use of an inorg. salt SbCl3 is reported for post-treatment on Sb2S3 films for surface passivation. It is found that a thin SbCl3 layer could form on the Sb2S3 surface and produce higher-efficiency cells by reducing the defects and suppressing nonradiative recombination. Through d. functional theory calcns., it is found that the passivation of the Sb2S3 surface by SbCl3 occurs via the interactions of Sb and Cl in SbCl3 mols. with S and Sb in Sb2S3, resp. As a result, incorporating the SbCl3 layer highly improves the VOC from 0.58 to 0.72 V; and an av. PCE of 6.9±0.1% and a highest PCE of 7.1% is obtained with an area of 0.1 cm2. The achieved PCE is the highest value in the Sb2S3 planar solar cells. In addn., the incorporated SbCl3 layer also leads to a good stability of Sb2S3 devices, by which 90% of initial performance is maintained for 1080 h storage under ambient humidity (85±5% relative humidity) at room temp.
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    24. 24
      Li, J.; Liu, X.; Yao, J. The Enhanced Photovoltaic Performance of Sb2S3 Solar Cells by Thermal Decomposition of Antimony Ethyl Xanthate with Thiourea Doping. Energy Technology 2020, 8 (4), 1900841,  DOI: 10.1002/ente.201900841
      24
      The Enhanced Photovoltaic Performance of Antimony trisulfide Solar Cells by Thermal Decomposition of Antimony Ethyl Xanthate with Thiourea Doping
      Li, Jihong; Liu, Xiaolong; Yao, Jianxi
      Energy Technology (Weinheim, Germany) (2020), 8 (4), 1900841CODEN: ETNEFN; ISSN:2194-4296. (Wiley-VCH Verlag GmbH & Co. KGaA)
      The thermal decompn. method is regarded as a simple and effective way to prep. Sb2S3 films. Herein, Antimony trisulfide films are prepd. by thermal decompns. of antimony Et xanthate (Sb(xt)3). During the thermal decompns. process, sulfur vacancy defects are easily formed because of high temps. To reduce the sulfur vacancy defects in the final Sb2S3 films, thiourea (TU) is introduced in the Sb(xt) precursor. By doping with TU, the crystallinity of the Sb2S3 films improves and dense Sb2S3 films are formed. With the decrease in sulfur defects, the carrier concns. are greatly increased from 2.5 × 1016 to 6.2 × 1016 cm-3. Compared with the no-doping Sb2S3 solar cells, the power conversion efficiency of Sb2S3 solar cells with doping 25% TU is improved from 2.85% to 3.70%.
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    25. 25
      Eensalu, J. S.; Tõnsuaadu, K.; Oja Acik, I.; Krunks, M. Sb2S3 Thin Films by Ultrasonic Spray Pyrolysis of Antimony Ethyl Xanthate. Mater. Sci. Semicond. Process. 2022, 137, 106209  DOI: 10.1016/j.mssp.2021.106209
      25
      Sb2S3 thin films by ultrasonic spray pyrolysis of antimony ethyl xanthate
      Eensalu, Jako S.; Tonsuaadu, Kaia; Oja Acik, Ilona; Krunks, Malle
      Materials Science in Semiconductor Processing (2022), 137 (), 106209CODEN: MSSPFQ; ISSN:1369-8001. (Elsevier Ltd.)
      Synthesis of antimony chalcogenides, esp. Sb2S3, by facile and area scalable in-air chem. methods, such as spray pyrolysis, from cost-effective chems. is certain to accelerate development of the related thin film solar cell technol. In this study, antimony Et xanthate, a scarcely studied halogenide-free precursor, is proven to be suitable for the deposition of conformal phase pure cryst. Sb2S3thin films via ultrasonic spray pyrolysis in air by a two-step process. First, a soln. of antimony Et xanthate with thiourea in a molar ratio of 1/3, or with thioacetamide in a molar ratio of 1/10 was sprayed onto a glass/ITO/TiO2 substrate by ultrasonic spray pyrolysis at 215°C to yield amorphous phase pure Sb2S3thin films. Second, performing post-growth heat treatment in vacuum at 225°C, was the key to produce phase pure conformal thin films of cryst. Sb2S3(Eg 1.8 eV) with S/Sb at. ratio of 1.46 by using thiourea, and 1.41 by using thioacetamide, resp. Spraying solns. of antimony Et xanthate at ≥135°C resulted in the formation of the Sb2O3 phase. Adding thiourea or thioacetamide to the spray soln. prevented the oxidn. of the growing Sb2S3layer during deposition at 135°C, 165°C, and 215°C. The suppressed oxidn. of Sb2S3layers is attributed to the liq. state of thiourea and thioacetamide in these conditions.
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    26. 26
      Eensalu, J. S.; Katerski, A.; Kärber, E.; Weinhardt, L.; Blum, M.; Heske, C.; Yang, W.; Oja Acik, I.; Krunks, M. Semitransparent Sb2S3 Thin Film Solar Cells by Ultrasonic Spray Pyrolysis for Use in Solar Windows. Beilstein J. Nanotechn. 2019, 10, 2396– 2409,  DOI: 10.3762/bjnano.10.230
      There is no corresponding record for this reference.
    27. 27
      Tamm, A.; Acik, I. O.; Arroval, T.; Kasikov, A.; Seemen, H.; Marandi, M.; Krunks, M.; Mere, A.; Kukli, K.; Aarik, J. Plasmon Resonance Effect Caused by Gold Nanoparticles Formed on Titanium Oxide Films. Thin Solid Films 2016, 616, 449– 455,  DOI: 10.1016/j.tsf.2016.08.059
      27
      Plasmon resonance effect caused by gold nanoparticles formed on titanium oxide films
      Tamm, Aile; Acik, Ilona Oja; Arroval, Tonis; Kasikov, Aarne; Seemen, Helina; Marandi, Margus; Krunks, Malle; Mere, Arvo; Kukli, Kaupo; Aarik, Jaan
      Thin Solid Films (2016), 616 (), 449-455CODEN: THSFAP; ISSN:0040-6090. (Elsevier B.V.)
      Gold nanoparticles were distributed by spray pyrolysis technique on bare glass substrates and on glass covered by titanium dioxide thin films grown by at. layer deposition, and were embedded in titanium dioxide layers. Plasmonic absorption was detected in the visible spectral range. The particles deposited on glass and on 80 nm thick titanium dioxide film resulted in appearance of an absorption band peaking at 550 nm. The plasmonic absorption maxima shifted towards longer wavelengths after embedding the particles into a top TiO2 layer. Atomic layer deposition of TiO2 films assisted in fixing and sepg. the metal particles on the surface, without destructive influence on the plasmonic behavior.
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    28. 28
      Hobson, T. D. C.; Durose, K. Protocols for the Miller Indexing of Sb2Se3 and a Non-x-Ray Method of Orienting Its Single Crystals. Mater. Sci. Semicond. Process. 2021, 127, 105691  DOI: 10.1016/j.mssp.2021.105691
      28
      Protocols for the Miller indexing of Sb2Se3 and a non-x-ray method of orienting its single crystals
      Hobson, T. D. C.; Durose, K.
      Materials Science in Semiconductor Processing (2021), 127 (), 105691CODEN: MSSPFQ; ISSN:1369-8001. (Elsevier Ltd.)
      The Sb2Se3 is a highly anisotropic semiconductor and unambiguous Miller indexing of its planes and diffraction patterns is therefore important - as is the prepn. of oriented and indexed surfaces of single crystals for fundamental studies. The purpose of this letter is twofold: (a) to bring attention to the two different Miller indexing conventions in popular use for Sb2Se3, (Space group No. 62, settings Pnma and Pbnm) explaining how they are related to its crystal structure and making recommendations for reporting protocols, and (b) to draw attention to a non-x-ray method of prepg. the three {100} type faces of single crystals of Sb2Se3 for use in phys. investigations.
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    29. 29
      Whittles, T. J.; Burton, L. A.; Skelton, J. M.; Walsh, A.; Veal, T. D.; Dhanak, V. R. Band Alignments, Valence Bands, and Core Levels in the Tin Sulfides SnS, SnS2, and Sn2S3: Experiment and Theory. Chem. Mater. 2016, 28 (11), 3718– 3726,  DOI: 10.1021/acs.chemmater.6b00397
      29
      Band Alignments, Valence Bands, and Core Levels in the Tin Sulfides SnS, SnS2, and Sn2S3: Experiment and Theory
      Whittles, Thomas J.; Burton, Lee A.; Skelton, Jonathan M.; Walsh, Aron; Veal, Tim D.; Dhanak, Vin R.
      Chemistry of Materials (2016), 28 (11), 3718-3726CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
      Tin sulfide solar cells show relatively poor efficiencies despite attractive photovoltaic properties, and there is difficulty in identifying sep. phases, which are also known to form during Cu2ZnSnS4 depositions. The authors present x-ray photoemission spectroscopy (XPS) and inverse photoemission spectroscopy measurements of single crystal SnS, SnS2, and Sn2S3, with electronic-structure calcns. from d. functional theory (DFT). Differences in the XPS spectra of the three phases, including a large 0.9 eV shift between the 3d5/2 peak for SnS and SnS2, make this technique useful when identifying phase-pure or mixed-phase systems. Comparison of the valence band spectra from XPS and DFT reveals extra states at the top of the valence bands of SnS and Sn2S3, arising from the hybridization of lone pair electrons in Sn(II), which are not present for Sn(IV), as found in SnS2. This results in relatively low ionization potentials for SnS (4.71 eV) and Sn2S3 (4.66 eV), giving a more comprehensive explanation as to the origin of the poor efficiencies. The authors also demonstrate, by a band alignment, the large band offsets of SnS and Sn2S3 from other photovoltaic materials and highlight the detrimental effect on cell performance of secondary tin sulfide phase formation in SnS and CZTS films.
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    30. 30
      Chernenko, K.; Kivimaki, A.; Parna, R.; Wang, W.; Sankari, R.; Leandersson, M.; Tarawneh, H.; Pankratov, V.; Kook, M.; Kukk, E.; Reisberg, L.; Urpelainen, S.; Kaambre, T.; Siewert, F.; Gwalt, G.; Sokolov, A.; Lemke, S.; Alimov, S.; Knedel, J.; Kutz, O.; Seliger, T.; Valden, M.; Hirsimaki, M.; Kirm, M.; Huttula, M. Performance and Characterization of the FinEstBeAMS Beamline at the MAX IV Laboratory. J. Synchrotron Radiat. 2021, 28, 1620– 1630,  DOI: 10.1107/S1600577521006032
      30
      Performance and characterization of the FinEstBeAMS beamline at the MAX IV Laboratory
      Chernenko, Kirill; Kivimaeki, Antti; Paerna, Rainer; Wang, Weimin; Sankari, Rami; Leandersson, Mats; Tarawneh, Hamed; Pankratov, Vladimir; Kook, Mati; Kukk, Edwin; Reisberg, Liis; Urpelainen, Samuli; Kaeaembre, Tanel; Siewert, Frank; Gwalt, Grzegorz; Sokolov, Andrey; Lemke, Stephanie; Alimov, Svyatoslav; Knedel, Jeniffa; Kutz, Oliver; Seliger, Tino; Valden, Mika; Hirsimaeki, Mika; Kirm, Marco; Huttula, Marko
      Journal of Synchrotron Radiation (2021), 28 (5), 1620-1630CODEN: JSYRES; ISSN:1600-5775. (International Union of Crystallography)
      FinEstBeAMS (Finnish-Estonian Beamline for Atm. and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5 GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5-1300 eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazing-incidence plane grating monochromator to disperse the radiation. At photon energies below 70 eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examg. such characteristics as the quality of the gratings, photon energy calibration, photon energy resoln., available photon flux, polarization quality and focal spot size.
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    31. 31
      Zakaznova-Herzog, V. P.; Harmer, S. L.; Nesbitt, H. W.; Bancroft, G. M.; Flemming, R.; Pratt, A. R. High Resolution XPS Study of the Large-Band-Gap Semiconductor Stibnite (Sb2S3): Structural Contributions and Surface Reconstruction. Surf. Sci. 2006, 600 (2), 348– 356,  DOI: 10.1016/j.susc.2005.10.034
      31
      High resolution XPS study of the large-band-gap semiconductor stibnite (Sb2S3): Structural contributions and surface reconstruction
      Zakaznova-Herzog, V. P.; Harmer, S. L.; Nesbitt, H. W.; Bancroft, G. M.; Flemming, R.; Pratt, A. R.
      Surface Science (2006), 600 (2), 348-356CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)
      Conventional XPS and synchrotron radiation XPS (SRXPS) were used to probe the chem. state properties of stibnite (Sb2S3), a large-band-gap semiconductor of complex structure. The conventional spectra were obtained with a Kratos Axis Ultra XPS with magnetic confinement charge neutralization, which is very effective in minimizing both uniform charging and differential charging on this large-band-gap semiconductor. The narrow linewidths (much narrower than previously obtained) for single doublet fits (e.g. Sb 4d5/2 of 0.57 eV and S 2p3/2 of 0.63 eV) enabled the observation of a small peak on the low binding energy side of the Sb 3d and Sb 4d lines. With the aid of the very surface-sensitive Sb 4d SRXPS spectra, these low energy peaks are assigned to small Sb metal clusters at the surface after cleavage; the signal for these clusters increases with x-ray dose on the sample. A detailed anal. of the Sb 4d and S 2p linewidths concludes that the Sb 4d5/2 linewidth is larger than expected based on the inherent linewidth of the instrument and the Sb 4d lifetime width, and on comparison with the As 3d linewidth (0.52 eV) for the analogous As2S3. Also, the S 2p3/2 linewidth is substantially broader than the Sb 4d5/2 linewidth. These larger than expected linewidths are due to two structurally distinct Sb atoms and three structurally distinct S atoms in the Sb2S3 crystal structure. Accordingly, the Sb 4d and S 2p spectra were fitted to two and three doublets, resp., and the linewidth for all peaks is 0.53 eV. Using recent MO calcns., the doublets were assigned to the different structural Sb and S sites.
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    32. 32
      Hobson, T. D. C.; Phillips, L. J.; Hutter, O. S.; Durose, K.; Major, J. D. Defect Properties of Sb2Se3 Thin Film Solar Cells and Bulk Crystals. Appl. Phys. Lett. 2020, 116 (26), 261101,  DOI: 10.1063/5.0012697
      32
      Defect properties of Sb2Se3 thin film solar cells and bulk crystals
      Hobson, Theodore D. C.; Phillips, Laurie J.; Hutter, Oliver S.; Durose, K.; Major, Jonathan D.
      Applied Physics Letters (2020), 116 (26), 261101CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      As an absorber in photovoltaic devices, Sb2Se3 has rapidly achieved impressive power conversion efficiencies despite the lack of fundamental knowledge about its electronic defects. Here, we present a deep level transient spectroscopy (DLTS) study of deep level defects in both bulk crystal and thin film device material. DLTS study of Bridgman-grown n-type bulk crystals revealed traps at 358, 447, 505, and 685 meV below the conduction band edge. Of these, the energetically close pair at 447 and 505 meV could only be resolved using the isothermal transient spectroscopy (rate window variation) method. A completed Sb2Se3 thin film solar cell displayed similar trap spectra with traps identified at 378, 460, and 690 meV. The comparable nature of defects in thin film and bulk crystal material implies that there is minimal impact of polycrystallinity in Sb2Se3 supporting the concept of benign grain boundaries. (c) 2020 American Institute of Physics.
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    33. 33
      Eensalu, J. S.; Tõnsuaadu, K.; Adamson, J.; Oja Acik, I.; Krunks, M. Thermal Decomposition of Tris(O-Ethyldithiocarbonato)-Antimony(III)─a Single-Source Precursor for Antimony Sulfide Thin Films. J. Therm. Anal. Calorim. 2022, 147 (8), 4899– 4913,  DOI: 10.1007/s10973-021-10885-1
      33
      Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III)-a single-source precursor for antimony sulfide thin films
      Eensalu, Jako S.; Tonsuaadu, Kaia; Adamson, Jasper; Oja Acik, Ilona; Krunks, Malle
      Journal of Thermal Analysis and Calorimetry (2022), 147 (8), 4899-4913CODEN: JTACF7; ISSN:1388-6150. (Springer)
      Thermal decompn. of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aq. soln. of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, DTA and evolved gas anal. via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform IR spectroscopy (FTIR) and NMR (NMR) measurements, and quantified by NMR and elemental anal. Solid intermediates and final decompn. products of 1 prepd. in both atmospheres were detd. by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compd., where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degrdn. of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomps. at 90-170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO22- ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decompn. mechanism of 1 is described with chem. reactions based on EGA-MS and solid intermediate decompn. product anal.
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    34. 34
      Kärber, E.; Katerski, A.; Oja Acik, I.; Mere, A.; Mikli, V.; Krunks, M. Sb2S3 Grown by Ultrasonic Spray Pyrolysis and Its Application in a Hybrid Solar Cell. Beilstein J. Nanotechnol. 2016, 7, 1662– 1673,  DOI: 10.3762/bjnano.7.158
      34
      Sb2S3 grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell
      Karber, Erki; Katerski, Atanas; Acik, Ilona Oja; Mere, Arvo; Mikli, Valdek; Krunks, Malle
      Beilstein Journal of Nanotechnology (2016), 7 (), 1662-1673CODEN: BJNEAH; ISSN:2190-4286. (Beilstein-Institut zur Foerderung der Chemischen Wissenschaften)
      Chem. spray pyrolysis (CSP) is a fast wet-chem. deposition method in which an aerosol is guided by carrier gas onto a hot substrate where the decompn. of the precursor chems. occurs. The aerosol is produced using an ultrasonic oscillator in a bath of precursor soln. and guided by compressed air. The use of the ultrasonic CSP resulted in the growth of homogeneous and well-adhered layers that consist of submicron crystals of single-phase Sb2S3 with a bandgap of 1.6 eV if an abundance of sulfur source is present in the precursor soln. (SbCl3/SC(NH2)2 = 1:6) sprayed onto the substrate at 250 °C in air. Solar cells with glass-ITO-TiO2-Sb2S3-P3HT-Au structure and an active area of 1 cm2 had an open circuit voltage of 630 mV, short circuit c.d. of 5 mA/cm2, a fill factor of 42% and a conversion efficiency of 1.3%. Conversion efficiencies up to 1.9% were obtained from solar cells with smaller areas.
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    35. 35
      Don, C. H.; Shiel, H.; Hobson, T. D. C.; Savory, C. N.; Swallow, J. E. N.; Smiles, M. J.; Jones, L. A. H.; Featherstone, T. J.; Thakur, P. K.; Lee, T.-L.; Durose, K.; Major, J. D.; Dhanak, V. R.; Scanlon, D. O.; Veal, T. D. Sb 5s2 Lone Pairs and Band Alignment of Sb2Se3: A Photoemission and Density Functional Theory Study. J. Mater. Chem. C 2020, 8 (36), 12615– 12622,  DOI: 10.1039/D0TC03470C
      35
      Sb 5s2 lone pairs and band alignment of Sb2Se3: a photoemission and density functional theory study
      Don, Christopher H.; Shiel, Huw; Hobson, Theodore D. C.; Savory, Christopher N.; Swallow, Jack E. N.; Smiles, Matthew J.; Jones, Leanne A. H.; Featherstone, Thomas J.; Thakur, Pardeep K.; Lee, Tien-Lin; Durose, Ken; Major, Jonathan D.; Dhanak, Vinod R.; Scanlon, David O.; Veal, Tim D.
      Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2020), 8 (36), 12615-12622CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
      The presence of a lone pair of 5s electrons at the valence band max. (VBM) of Sb2Se3 and the resulting band alignments are investigated using soft and hard X-ray photoemission spectroscopy in parallel with d. functional theory (DFT) calcns. Vacuum-cleaved and exfoliated bulk crystals of Sb2Se3 are analyzed using lab. and synchrotron X-ray sources to acquire high resoln. valence band spectra with both soft and hard X-rays. Utilizing the photon-energy dependence of different orbital cross-sections and corresponding DFT calcns., the various orbital contributions to the valence band could be identified, including the 5s orbital's presence at the VBM. The ionization potential is also detd. and places the VBM at 5.13 eV below the vacuum level, similar to other materials with 5s2 lone pairs, but far above those of related materials without lone pairs of electrons.
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    36. 36
      Zhao, Y.; Wang, S.; Li, C.; Che, B.; Chen, X.; Chen, H.; Tang, R.; Wang, X.; Chen, G.; Wang, T.; Gong, J.; Chen, T.; Xiao, X.; Li, J. Regulating Deposition Kinetics via a Novel Additive-Assisted Chemical Bath Deposition Technology Enables Fabrication of 10.57%-Efficiency Sb2Se3 Solar Cells. Energy Environ. Sci. 2022, 15, 5118,  DOI: 10.1039/D2EE02261C
      36
      Regulating deposition kinetics via a novel additive-assisted chemical bath deposition technology enables fabrication of 10.57%-efficiency Sb2Se3 solar cells
      Zhao, Yuqi; Wang, Shaoying; Li, Chuang; Che, Bo; Chen, Xueling; Chen, Hongyi; Tang, Rongfeng; Wang, Xiaomin; Chen, Guilin; Wang, Ti; Gong, Junbo; Chen, Tao; Xiao, Xudong; Li, Jianmin
      Energy & Environmental Science (2022), 15 (12), 5118-5128CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
      Synthesizing high-quality films with superior morphol., elec., and defect properties is the basic requirement for obtaining high-efficiency solar cells. Recently, Sb2Se3 has been the emerging photovoltaic material with a low-symmetry crystal structure and complicated defect properties, giving a unique synthesis challenge for high-performance solar devices. In this work, we developed a novel additive-assisted chem. bath deposition (CBD) technol. for producing ideal antimony triselenide (Sb2Se3) films using antimony potassium tartrate and sodium selenosulfate as antimony and selenide sources, resp., with thiourea and selenourea as additives to manipulate the deposition process. We uncover that additive regulated deposition kinetics is essential to improve the film properties. Comprehensively, the phys. properties of Sb2Se3 films in terms of morphol., crystallinity, carrier transport properties, and defect d. have been significantly enhanced. As a result, we achieved a power conversion efficiency of 10.57% in Sb2Se3 solar cells, which represents the highest efficiency of Sb2Se3 solar cells, regardless of the fabrication methods and device structures. Given the scalability to large area prodn. and the low-cost fabrication characteristics of the CBD technique, this study demonstrates not only an effective and implementable method for fabricating highly efficient Sb2Se3 solar cells but also paves the way for industrial prodn. of large-area Sb2Se3 photovoltaic panels in the future.
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    37. 37
      Shiel, H.; Hobson, T. D. C.; Hutter, O. S.; Phillips, L. J.; Smiles, M. J.; Jones, L. A. H.; Featherstone, T. J.; Swallow, J. E. N.; Thakur, P. K.; Lee, T.-L.; Major, J. D.; Durose, K.; Veal, T. D. Band Alignment of Sb2O3 and Sb2Se3. J. Appl. Phys. (Melville, NY, U. S.) 2021, 129 (23), 235301,  DOI: 10.1063/5.0055366
      37
      Band alignment of Sb2O3 and Sb2Se3
      Shiel, Huw; Hobson, Theodore D. C.; Hutter, Oliver S.; Phillips, Laurie J.; Smiles, Matthew J.; Jones, Leanne A. H.; Featherstone, Thomas J.; Swallow, Jack E. N.; Thakur, Pardeep K.; Lee, Tien-Lin; Major, Jonathan D.; Durose, Ken; Veal, Tim D.
      Journal of Applied Physics (Melville, NY, United States) (2021), 129 (23), 235301CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
      Antimony selenide (Sb2Se3) possesses great potential in the field of photovoltaics (PV) due to its suitable properties for use as a solar absorber and good prospects for scalability. Previous studies have reported the growth of a native antimony oxide (Sb2O3) layer at the surface of Sb2Se3 thin films during deposition and exposure to air, which can affect the contact between Sb2Se3 and subsequent layers. In this study, photoemission techniques were utilized on both Sb2Se3 bulk crystals and thin films to investigate the band alignment between Sb2Se3 and the Sb2O3 layer. By subtracting the valence band spectrum of an in situ cleaved Sb2Se3 bulk crystal from that of the atmospherically contaminated bulk crystal, a valence band offset (VBO) of - 1.72 eV is measured between Sb2Se3 and Sb2O3. This result is supported by a - 1.90 eV VBO measured between Sb2O3 and Sb2Se3 thin films via the Kraut method. Both results indicate a straddling alignment that would oppose carrier extn. through the back contact of superstrate PV devices. This work yields greater insight into the band alignment of Sb2O3 at the surface of Sb2Se3 films, which is crucial for improving the performance of these PV devices. (c) 2021 American Institute of Physics.
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    38. 38
      Fleck, N.; Hutter, O. S.; Phillips, L. J.; Shiel, H.; Hobson, T. D. C.; Dhanak, V. R.; Veal, T. D.; Jäckel, F.; Durose, K.; Major, J. D. How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells. ACS Appl. Mater. Interfaces 2020, 12 (47), 52595– 52602,  DOI: 10.1021/acsami.0c14256
      38
      How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells
      Fleck, Nicole; Hutter, Oliver S.; Phillips, Laurie J.; Shiel, Huw; Hobson, Theodore D. C.; Dhanak, Vin R.; Veal, Tim D.; Jackel, Frank; Durose, Ken; Major, Jonathan D.
      ACS Applied Materials & Interfaces (2020), 12 (47), 52595-52602CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
      The improvement of antimony selenide solar cells by short-term air exposure is explained using complementary cell and material studies. We demonstrate that exposure to air yields a relative efficiency improvement of n-type Sb2Se3 solar cells of ca. 10% by oxidn. of the back surface and a redn. in the back contact barrier height (measured by J-V-T) from 320 to 280 meV. XPS measurements of the back surface reveal that during 5 days in air, Sb2O3 content at the sample surface increased by 27%, leaving a more Se-rich Sb2Se3 film along with a 4% increase in elemental Se. Conversely, exposure to 5 days of vacuum resulted in a loss of Se from the Sb2Se3 film, which increased the back contact barrier height to 370 meV. Inclusion of a thermally evapd. thin film of Sb2O3 and Se at the back of the Sb2Se3 absorber achieved a peak solar cell efficiency of 5.87%. These results demonstrate the importance of a Se-rich back surface for high-efficiency devices and the pos. effects of an ultrathin antimony oxide layer. This study reveals a possible role of back contact etching in exposing a beneficial back surface and provides a route to increasing device efficiency.
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      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXit1ynsbbL&md5=027de17d6fcdd31ee14de357627dbfb5
    39. 39
      Castner, D. G.; Hinds, K.; Grainger, D. W. X-Ray Photoelectron Spectroscopy Sulfur 2p Study of Organic Thiol and Disulfide Binding Interactions with Gold Surfaces. Langmuir 1996, 12 (21), 5083– 5086,  DOI: 10.1021/la960465w
      39
      X-ray Photoelectron Spectroscopy Sulfur 2p Study of Organic Thiol and Disulfide Binding Interactions with Gold Surfaces
      Castner, David G.; Hinds, Kenneth; Grainger, David W.
      Langmuir (1996), 12 (21), 5083-5086CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
      The presence of 2 S species was detected in XPS studies of thiol and disulfide mols. adsorbed on Au surfaces. These species are assigned to bound thiolate (S2p3/2 binding energy 162 eV) and unbound thiol/disulfide (S2p3/2 binding energy from 163.5 to 164 eV). These assignments are consistent with XPS data obtained from different thiols (C12, C16, C18, and C22 alkane thiols, a fluorinated thiol, and a cyclic siloxanethiol) and different adsorption conditions (solvent type, thiol concn., temp., and rinsing). In particular, the use of a poor solvent for thiol adsorption solns. (e.g., EtOH for long chain alkanethiols) and the lack of a rinsing step both resulted in unbound thiol mols. present at the surface of the bound thiolate monolayer. This has implications for recent studies asserting the presence of multiple binding sites for Au-thiolate species in org. monolayers.
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    40. 40
      Hobson, T. D. C.; Shiel, H.; Savory, C. N.; Swallow, J. E. N.; Jones, L. A. H.; Featherstone, T. J.; Smiles, M. J.; Thakur, P. K.; Lee, T.-L.; Das, B.; Leighton, C.; Zoppi, G.; Dhanak, V. R.; Scanlon, D. O.; Veal, T. D.; Durose, K.; Major, J. D. P-Type Conductivity in Sn-Doped Sb2Se3. J. Phys.: Energy 2022, 4 (4), 045006  DOI: 10.1088/2515-7655/ac91a6
      There is no corresponding record for this reference.
    41. 41
      Yin, Y.; Wu, C.; Tang, R.; Jiang, C.; Jiang, G.; Liu, W.; Chen, T.; Zhu, C. Composition Engineering of Sb2S3 Film Enabling High Performance Solar Cells. Sci. Bull. 2019, 64 (2), 136– 141,  DOI: 10.1016/j.scib.2018.12.013
      41
      Composition engineering of Sb2S3 film enabling high performance solar cells
      Yin, Yiwei; Wu, Chunyan; Tang, Rongfeng; Jiang, Chenhui; Jiang, Guoshun; Liu, Weifeng; Chen, Tao; Zhu, Changfei
      Science Bulletin (2019), 64 (2), 136-141CODEN: SBCUA5; ISSN:2095-9281. (Elsevier B.V.)
      Sb2S3 is a kind of stable light absorption materials with suitable band gap, promising for practical applications. Here we demonstrate that the engineering on the compn. ratio enables significant improvement in the device performance. We found that the co-evapn. of sulfur or antimony with Sb2S3 is able to generate sulfur- or antimony-rich Sb2S3. This compn. does not generate essential influence on the crystal structure, optical band and film formability, while the carrier concn. and transport dynamics are considerably changed. The device investigations show that sulfur-rich Sb2S3 film is favorable for efficient energy conversion, while antimony-rich Sb2S3 leads to greatly decreased device performance. With optimizations on the sulfur-rich Sb2S3 films, the final power conversion efficiency reaches 5.8%, which is the highest efficiency in thermal evapn. derived Sb2S3 solar cells.
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    42. 42
      Darga, A.; Mencaraglia, D.; Longeaud, C.; Savenije, T. J.; O’Regan, B.; Bourdais, S.; Muto, T.; Delatouche, B.; Dennler, G. On Charge Carrier Recombination in Sb2S3 and Its Implication for the Performance of Solar Cells. J. Phys. Chem. C 2013, 117 (40), 20525– 20530,  DOI: 10.1021/jp4072394
      42
      On charge carrier recombination in Sb2S3 and its implication for the performance of solar cells
      Darga, Arouna; Mencaraglia, Denis; Longeaud, Christophe; Savenije, Tom J.; O'Regan, Brian; Bourdais, Stephane; Muto, Takuma; Delatouche, Bruno; Dennler, Gilles
      Journal of Physical Chemistry C (2013), 117 (40), 20525-20530CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
      Sb2S3 is widely considered to be an attractive photovoltaic material based on abundant, nontoxic elements. However, the max. efficiency reported for solar cells based on this semiconductor does not exceed 6.5%. We have measured light intensity-dependent J-V curves, transient microwave photocond., steady-state photocurrent grating, modulated photocurrent, and photocond. on Sb2S3-based samples. All techniques converge toward the same observation: the main recombination route controlling the d. of charge carriers in the absorber is of an order greater than one and appears to stem from an exponentially decaying d. of tail states within the conduction band of the material. This conclusion has direct and drastic implications for the performance of Sb2S3-based solar cells.
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    43. 43
      Rau, U.; Schock, H. W. Electronic Properties of Cu(In,Ga)Se2 Heterojunction Solar Cells–Recent Achievements, Current Understanding, and Future Challenges. Appl. Phys. A: Mater. Sci. Process. 1999, 69 (2), 131– 147,  DOI: 10.1007/s003390050984
      43
      Electronic properties of Cu(In,Ga)Se2 heterojunction solar cells. Recent achievements, current understanding, and future challenges
      Rau, Uwe; Schock, H. W.
      Applied Physics A: Materials Science & Processing (1999), 69 (2), 131-147CODEN: APAMFC; ISSN:0947-8396. (Springer-Verlag)
      The recent achievements of high-efficiency Cu(In,Ga)Se2 heterojunction solar cells are reviewed with 187 refs. with a special focus on the understanding of the electronic transport properties of the devices. Th authors discuss the basic limitations of the device performance, the present understanding of electronic device anal., as well as the role of intrinsic defects and of the interfaces for the performance of the solar cells.
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    44. 44
      Wang, R.; Wang, Y.; Pan, Y.; Qin, D.; Weng, G.; Hu, X.; Tao, J.; Luo, X.; Chen, S.; Zhu, Z.; Chu, J.; Akiyama, H. Improving the Performance of Sb2S3 Thin-Film Solar Cells by Optimization of VTD Source-Substrate Proximity. Sol. Energy 2021, 220, 942– 948,  DOI: 10.1016/j.solener.2021.03.052
      44
      Improving the performance of Sb2S3 thin-film solar cells by optimization of VTD source-substrate proximity
      Wang, Rui; Wang, Youyang; Pan, Yanlin; Qin, Deyang; Weng, Guoen; Hu, Xiaobo; Tao, Jiahua; Luo, Xianjia; Chen, Shaoqiang; Zhu, Ziqiang; Chu, Junhao; Akiyama, Hidefumi
      Solar Energy (2021), 220 (), 942-948CODEN: SRENA4; ISSN:0038-092X. (Elsevier Ltd.)
      In this paper, Sb2S3 thin-film solar cells are fabricated by the vapor transport deposition (VTD) method. The effect of the source-substrate proximity on the performance of Sb2S3 thin-film solar cells has been investigated and comparative studies of different source-substrate proximity are carried out. The device efficiency is improved from 0.83 to 3.02% by optimizing the source-substrate proximity with the augment of open-circuit voltage, short-circuit c.d. and fill factor. X-ray diffraction and SEM studies indicate that the deposited Sb2S3 films can achieve optimal grain orientation, high crystallinity, and compact morphol. Moreover, the current transport mechanism is analyzed in detail from dark c.d.-voltage (J-V) measurements and shows the optimal sample to be least affected by Shockley-Read-Hall recombination and space-charge-limited current (SCLC). Meanwhile, temp. and light intensity-dependent open-circuit voltage measurements reveal the carrier recombination rates are lowest for the optimal cell in all regions, including the CdS/Sb2S3 interface, the space-charge region (SCR), and the quasi-neutral region (QNR). These can account for the efficiency enhancement of the optimal cell and can be used to facilitate the further development of Sb2S3 thin-film solar cells.
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    45. 45
      Hu, X.; Tao, J.; Wang, R.; Wang, Y.; Pan, Y.; Weng, G.; Luo, X.; Chen, S.; Zhu, Z.; Chu, J.; Akiyama, H. Fabricating over 7%-Efficient Sb2(S,Se)3 Thin-Film Solar Cells by Vapor Transport Deposition Using Sb2Se3 and Sb2S3 Mixed Powders as the Evaporation Source. J. Power Sources 2021, 493, 229737  DOI: 10.1016/j.jpowsour.2021.229737
      45
      Fabricating over 7%-efficient Sb2(S,Se)3 thin-film solar cells by vapor transport deposition using Sb2Se3 and Sb2S3 mixed powders as the evaporation source
      Hu, Xiaobo; Tao, Jiahua; Wang, Rui; Wang, Youyang; Pan, Yanlin; Weng, Guoen; Luo, Xianjia; Chen, Shaoqiang; Zhu, Ziqiang; Chu, Junhao; Akiyama, Hidefumi
      Journal of Power Sources (2021), 493 (), 229737CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
      In this study, Sb2(S,Se)3 thin films are fabricated using the vapor transport deposition (VTD) method, with Sb2Se3 and Sb2S3 mixed powders as the evapn. source. The performance of the corresponding glass/ITO/CdS/Sb2(S,Se)3/Au solar cells are found to be correlated to the mass ratio between Sb2S3 and the overall powder mixt. The properties of the Sb2(S,Se)3 thin films and cell devices adopting four different Sb2S3 mass ratios (x = 0.1, 0.25, 0.5 and 0.75) are compared. Further, the elec. properties - from dark and light J-V measurements; structural properties - from X-ray diffraction and scanning electron microscope measurements; and carrier-recombination rates at the buffer/absorber interface in the space-charge region (SCR) and in the quasi-neutral region - from temp.-illumination-dependent open-circuit voltage (VOC) measurements - are compared. It is found that a Sb2(S,Se)3 solar cell with a Sb2S3 mass ratio of 0.25 had optimal crystallinity, the lowest d. of deep traps and the smallest carrier-recombination rates at the interface, leading to a high efficiency of 7.31%.
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    46. 46
      Kauk-Kuusik, M.; Timmo, K.; Muska, K.; Pilvet, M.; Krustok, J.; Danilson, M.; Mikli, V.; Josepson, R.; Grossberg-Kuusk, M. Reduced Recombination through CZTS/CdS Interface Engineering in Monograin Layer Solar Cells. J. Phys.: Energy 2022, 4 (2), 024007  DOI: 10.1088/2515-7655/ac618d
      There is no corresponding record for this reference.
    47. 47
      Lee, S. W.; Keum, H.-S.; Kim, H. S.; Kim, H. J.; Ahn, K.; Lee, D. R.; Kim, J. H.; Lee, H. H. Temperature-Dependent Evolution of Poly(3-Hexylthiophene) Type-II Phase in a Blended Thin Film. Macromol. Rapid Commun. 2016, 37 (3), 203– 208,  DOI: 10.1002/marc.201500527
      47
      Temperature-Dependent Evolution of Poly(3-Hexylthiophene) Type-II Phase in a Blended Thin Film
      Lee, Si Woo; Keum, Hee-Sung; Kim, Han Seong; Kim, Hyo Jung; Ahn, Kwangseok; Lee, Dong Ryeol; Kim, Je Han; Lee, Hyun Hwi
      Macromolecular Rapid Communications (2016), 37 (3), 203-208CODEN: MRCOE3; ISSN:1022-1336. (Wiley-VCH Verlag GmbH & Co. KGaA)
      The structure of P3HT in P3HT:PCBM films is examd. on a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) substrate subjected to cryo-cooling to low temp. (-143 °C) followed by gradual heating to 50 °C. The behavior of these systems is examd. in the absence and presence of an Al electrode on top of the P3HT:PCBM film. At temps. below -10 °C, only the type-I phase of P3HT is obsd. However, the type-II phase of P3HT starts to form near -10 °C, in both the presence and absence of the Al layer. In the system without an Al layer, the type-II phase disappears at 30 °C, but this phase persists to 50 °C in the presence of the Al layer. Concomitant with the formation of the type-II phase, a 1:3 ordered P3HT type-II (1/3,0,0) superlattice peak emerged. The type-II domains tend to form near the Al electrode layer and show a higher degree of alignment than the type-I crystals.
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    48. 48
      Grigas, J.; Karpus, A. Dielectric Properties of Sb2S3 Crystals. Phys. Solid State 1967, 9, 2882– 2886
      There is no corresponding record for this reference.
    49. 49
      Nadenau, V.; Rau, U.; Jasenek, A.; Schock, H. W. Electronic Properties of CuGaSe2-Based Heterojunction Solar Cells. Part I. Transport Analysis. J. Appl. Phys. (Melville, NY, U. S.) 2000, 87 (1), 584– 593,  DOI: 10.1063/1.371903
      There is no corresponding record for this reference.
    50. 50
      Beck, H. E.; Zimmermann, N. E.; McVicar, T. R.; Vergopolan, N.; Berg, A.; Wood, E. F. Present and Future Köppen-Geiger Climate Classification Maps at 1-Km Resolution. Sci. Data 2018, 5 (1), 180214  DOI: 10.1038/sdata.2018.214
      50
      Present and future Koppen-Geiger climate classification maps at 1-km resolution
      Beck Hylke E; Vergopolan Noemi; Berg Alexis; Wood Eric F; Zimmermann Niklaus E; Zimmermann Niklaus E; McVicar Tim R; McVicar Tim R
      Scientific data (2018), 5 (), 180214 ISSN:.
      We present new global maps of the Koppen-Geiger climate classification at an unprecedented 1-km resolution for the present-day (1980-2016) and for projected future conditions (2071-2100) under climate change. The present-day map is derived from an ensemble of four high-resolution, topographically-corrected climatic maps. The future map is derived from an ensemble of 32 climate model projections (scenario RCP8.5), by superimposing the projected climate change anomaly on the baseline high-resolution climatic maps. For both time periods we calculate confidence levels from the ensemble spread, providing valuable indications of the reliability of the classifications. The new maps exhibit a higher classification accuracy and substantially more detail than previous maps, particularly in regions with sharp spatial or elevation gradients. We anticipate the new maps will be useful for numerous applications, including species and vegetation distribution modeling. The new maps including the associated confidence maps are freely available via www.gloh2o.org/koppen.
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    51. 51
      Artegiani, E.; Major, J. D.; Shiel, H.; Dhanak, V.; Ferrari, C.; Romeo, A. How the Amount of Copper Influences the Formation and Stability of Defects in CdTe Solar Cells. Sol. Energy Mater. Sol. Cells 2020, 204, 110228  DOI: 10.1016/j.solmat.2019.110228
      51
      How the amount of copper influences the formation and stability of defects in CdTe solar cells
      Artegiani, Elisa; Major, Jonathan D.; Shiel, Huw; Dhanak, Vin; Ferrari, Claudio; Romeo, Alessandro
      Solar Energy Materials & Solar Cells (2020), 204 (), 110228CODEN: SEMCEQ; ISSN:0927-0248. (Elsevier B.V.)
      With a 22.1% efficiency record and the successful results in terms of prodn. yield, CdTe based thin film solar cells are today a competing technol. with traditional silicon solar cells. Despite different copper-free back contacts have been applied, Cu is present in all the most performing CdTe devices. On the other hand, it is well known that Cu is a fast diffuser in CdTe, and it heavily influences the devices degrdn.; thus controlling its concn. is very important. In this paper a study of the influence of copper quantity on the performance of the devices and stability at the back contact is presented. CdTe cells fabricated with a 0.1 nm thick Cu layer are compared to devices fabricated with 2.0, 1.0 and 0.5 nm thick Cu layers. The amt. of copper affects the performance and aging of the samples. Moreover an inversion of the bias dependency (solar cells in open circuit or in short circuit under current flow), during the aging, occurs in samples contg. a copper layer below a certain thickness, suggesting that another degrdn. mechanism predominates.
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    52. 52
      Thompson, C. V. Solid-State Dewetting of Thin Films. Annu. Rev. Mater. Res. 2012, 42 (1), 399– 434,  DOI: 10.1146/annurev-matsci-070511-155048
      52
      Solid-state dewetting of thin films
      Thompson, Carl V.
      Annual Review of Materials Research (2012), 42 (), 399-434CODEN: ARMRCU; ISSN:1531-7331. (Annual Reviews Inc.)
      A review. Solid films are usually metastable or unstable in the as-deposited state, and they will dewet or agglomerate to form islands when heated to sufficiently high temps. This process is driven by surface energy minimization and can occur via surface diffusion well below a film's melting temp., esp. when the film is very thin. Dewetting during processing of films for use in micro- and nanosystems is often undesirable, and means of avoiding dewetting are important in this context. However, dewetting can also be useful in making arrays of nanoscale particles for electronic and photonic devices and for catalyzing growth of nanotubes and nanowires. Templating of dewetting using patterned surface topog. or prepatterning of films can be used to create ordered arrays of particles and complex patterns of partially dewetted structures. Studies of dewetting can also provide fundamental new insight into the effects of surface energy anisotropy and facets on shape evolution.
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    53. 53
      Itzhaik, Y.; Niitsoo, O.; Page, M.; Hodes, G. Sb2S3-Sensitized Nanoporous TiO2 Solar Cells. J. Phys. Chem. C 2009, 113 (11), 4254– 4256,  DOI: 10.1021/jp900302b
      53
      Sb2S3-Sensitized Nanoporous TiO2 Solar Cells
      Itzhaik, Yafit; Niitsoo, Olivia; Page, Miles; Hodes, Gary
      Journal of Physical Chemistry C (2009), 113 (11), 4254-4256CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
      Extremely Thin Absorber (ETA) solar cells were made using chem.-bath-deposited Sb2S3 as the absorber and TiO2/CuSCN as the interpenetrating electron/hole conductors. A solar conversion efficiency of 3.37% at 1 sun illumination was obtained. Surface oxidn. of the Sb2S3 formed a passivation layer on Sb2S3 - without this oxidn. much poorer cells were obtained. Preliminary measurements showed good stability over 3 days of illumination (at 60 mW/cm2) under load.
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  • Supporting Information

    Supporting Information

    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.3c08547.

    • List of chemicals used, additional UV–vis and EQE spectra, UV–vis spectra, I–V statistics, and optical microscope images of the deposition time series, SEM images, tabulated I–V–T and XPS fit results, Pearson correlation graphs, 2D XPS data, and PES fit curves for the partial solar cell stacks (PDF)


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