Fossil fuel is the main energy resource currently. The continuous consumption of this nonrenewable resource has caused very serious environment problems, which has motivated tremendous research efforts in this century. Energy storage is critical to alleviate the current energy and environmental problems. Comparing to mechanical energy storage, rechargeable batteries allow energy storage with a smaller footprint. The intersection of rechargeable battery with nanomaterials has been a booming research topic recently and yielded new applications of nanomaterials as well as new solutions to many long-lived problems in battery science and technology. In this Perspective, we highlight the most recent (2015–2017) examples across lithium, sodium and zinc battery chemistries, where nanoscale materials tailoring and design addresses the intrinsic problems and limitations at both the materials level and device level. And a few principles are generalized at the end.

Rare-earth-based pnictide oxides (RE,Ca)mPnnOm (Pn = Sb, Bi) adopt a variety of interrelated structures based on specific stacking sequences of rare-earth oxide sublattices. These phases are all prepared via high temperature reactions and may be selectively produced in high purity. X-ray single crystal studies also revealed the disorder of pnictogen atoms in the non-charge balanced structures, which gives rise to unexpected physical properties. It is theorized that Anderson localization of the Pn p states results in an activation energy which forces semiconductor-type behavior in these phases. Interestingly, the extent of the localization of states is directly dependent on the magnitude of the disorder of the pnictogen atom, which also depends on pnictogen and/or the rare-earth atom that is used. By altering the composition of the sample with respect to the choice of Pn and/or RE, the physical properties of these select phases may be tuned to the desirable level without a change to the overall structure. The progression of this series of phases with respect to chemistry, structure, and physical properties is reviewed and discussed.

Here we report the selective growth of well-dispersed metal–organic framework (MOF) nanocrystals within mesoporous materials via novel “solid-state” synthesis. The ability to control and direct the growth of MOFs on confined surfaces (pores) paves the way for new prospective applications of such hybrid systems and could unlock the full potential of these materials. As confirmed by a combination of different characterization techniques, an outstanding high loading of mesoporous cavities (≤40 wt %) by the smallest MOF crystals yet reported (4.5 ± 1 nm) leads to several improved properties, including diffusion, attrition resistance, and handling.

The oxide with nominal composition Li7La3Zr2O12 (LLZO) is a promising solid electrolyte thanks to its high (bulk) Li-ion conductivity, negligible electronic transport, chemical stability against Li metal, and wide electrochemical window. Despite these promising characteristics, recent measurements suggest that microstructural features, specifically, grain boundaries (GBs), contribute to undesirable short-circuiting and resistance in polycrystalline LLZO membranes. Toward the goal of understanding GB-related phenomena, the present study characterizes the energetics, composition, and transport properties of three low-energy (Σ3 and Σ5) symmetric tilt GBs in LLZO at the atomic scale. Monte Carlo simulations reveal that the GB planes are enriched with Li, and to a lesser extent with oxygen. Molecular dynamics simulations on these off-stoichiometric boundaries were used to assess Li-ion transport within and across the boundary planes. We find that Li transport is generally reduced in the GB region; however, the magnitude of this effect is sensitive to temperature and GB structure. Li-ion diffusion is comparable in all three GBs at the high temperatures encountered during processing, and only 2–3 times slower than bulk diffusion. These similarities vanish at room temperature, where diffusion in the more compact Σ3 boundary remains relatively fast (half the bulk rate), while transport in the Σ5 boundaries is roughly 2 orders of magnitude slower. These trends mirror the activation energies for diffusion, which in the Σ5 boundaries are up to 35% larger than in bulk LLZO, and are identical to the bulk in the Σ3 boundary. Diffusion within the Σ5 boundaries is observed to be isotropic. In contrast, intraplane diffusion in the Σ3 boundary plane at room temperature is predicted to exceed that of the bulk, while transboundary diffusion is ∼200 times slower than that in the bulk. Our observation of mixed GB transport contributions (some boundaries support fast diffusion, while others are slow) is consistent with the limited GB resistance observed in polycrystalline LLZO samples processed at high temperatures. These data also suggest that higher-energy GBs with less-compact structures should penalize Li-ion conductivity to a greater degree.

Thermal decomposition is a promising route for the synthesis of highly monodisperse magnetite nanoparticles. However, the apparent simplicity of the synthesis is counterbalanced by the complex interplay of the reagents with the reaction variables that determine the final particle size and dispersity. Here, we present a combined experimental and theoretical study on the influence of the heating rate on crystal growth, size, and monodispersity of iron oxide nanoparticles. We synthesized monodisperse nanoparticles with sizes varying from 6.3 to 27 nm simply by controlling the heating rate of the reaction. The nanoparticles show size-dependent superparamagnetic behavior. Using numerical calculations based on the classical nucleation theory and growth model, we identified the relative time scales associated with the heating rate and precursor-to-monomer (growth species) conversion rate as a decisive factor influencing the final size and dispersity of the nanoparticles.

Close-packed chalcogenide spinels, such as MgSc2Se4, MgIn2S4, and MgSc2S4, show potential as solid electrolytes in Mg batteries, but are affected by non-negligible electronic conductivity, which contributes to self-discharge when used in an electrochemical storage device. Using first-principles calculations, we evaluate the energy of point defects as a function of synthesis conditions and Fermi level to identify the origins of the undesired electronic conductivity. Our results suggest that Mg-vacancies and Mg-metal antisites (where Mg is exchanged with Sc or In) are the dominant point defects that can occur in the systems under consideration. While we find anion-excess conditions and slow cooling to likely create conditions for low electronic conductivity, the spinels are likely to exhibit significant n-type conductivity under anion-poor environments, which are often present during high-temperature synthesis. Finally, we explore extrinsic aliovalent doping to potentially mitigate the electronic conductivity in these chalcogenide spinels. The computational strategy is general and can be easily extended to other solid electrolytes (and electrodes) to aid the optimization of the electronic properties of the corresponding frameworks.

Supramolecular metal-phenolic thin films attract an increasing interest since they allow the design of new types of self-assembling materials, such as tunable electronics or biomaterials. In this study, a new electrotriggered self-assembly of tannic acid-Fe(III) (TA-Fe(III)) nanocoatings was developed using the morphogenic approach with Fe(III) ions as a morphogen. Morphogens are molecules or ions produced locally that diffuse into the solution and induce a chemical reaction or interaction in a confined space near a surface. Using a mixture of TA and Fe(II) ions in contact with an electrode, a confined electrogenerated gradient of Fe(III) was obtained by application of an anodic current to locally form TA-Fe(III) coordination complexes. TA-Fe(III) nanocoatings, based on di- and tri-coordinated complexes, were thus obtained. Both the film thickness and its self-assembly kinetics were tuned by controlling the Fe(II)/TA molar ratio of the building solution, the intensity, and the duration of the applied current. We showed that this strategy can be applied to two other polyphenols (gallic acid and rosmarinic acid). This new electrotriggered confined self-assembly of metal–polyphenol gives new perspectives in applications such as antioxidant coating.

Developing an efficient and low-cost synthetic approach to controllably synthesize non-precious-metal counter electrode (CE) electrocatalysts with superior catalytic activity and electrochemical stability is critically important for the mass production of dye-sensitized solar cells (DSSCs). Herein, we proposed a simple, economical, and easily scalable synthetic route for copyrolysis of melamine and nickel acetate precursors to access the well-defined Ni-encapsulated and nitrogen-doped carbon nanotubes (Ni-NCNTs). The synthetic mechanism was comprehensively investigated by creatively analyzing the phase structure evolution and dynamical decomposition behaviors, and revealed the construction of Ni-NCNTs based on the Ni-catalyzed tip-growth mechanism. Furthermore, the meticulous structural design of Ni nanoparticles intercalated in N-doped CNTs endows Ni-NCNTs with homogeneously distributed Ni–C interfaces, abundant structural defects, and a porous architecture, as well as good electrical conductivity and corrosion-resistance properties. When used as counter electrode for DSSCs, the device delivers a high power conversion efficiency of 8.94% under simulated sunlight (AM 1.5, 100 mW cm–2) and long-term stability with a remnant efficiency of 8.34% after 100 h of illumination, superior to those of conventional Pt. The outstanding catalytic performance of Ni-NCNTs was mainly attributed to the synergetic effect of intercalated Ni with N-doped CNTs at the unique Ni–C interfaces, and the concomitant electronic interaction of Ni and N with C atoms in the interfacial nanoregime. The systematic studies on the synthetic mechanism and structure–activity relationship provide a new insight into the rational design of structural and electronic properties for high-performance Ni-NCNT CEs, as well as into the fundamental understanding of their catalytic mechanism for triiodide reduction.

Postdeposition treatments (PDTs) with sodium fluoride (NaF) and potassium fluoride (KF) were introduced as a way to improve the efficiency of Cu(In,Ga)Se2 (CIGS) based solar cells. Here, we apply postdeposition treatments with rubidium fluoride (RbF) to low-temperature coevaporated CIGS absorbers after a first PDT with NaF and compare the effects of the addition of Rb and K on the solar cell performance and material properties of the CIGS films. KF and RbF PDTs lead to similar improvements in the open-circuit voltage (Voc) and fill factor (FF), while allowing a reduction of the thickness of the cadmium sulfide (CdS) buffer layer without loss in electronic performance. KF and RbF PDTs lead to comparable modifications of the morphology and composition of the CIGS films. After the PDT, K and Rb accumulate in a nanopatterned copper-poor secondary phase at the CIGS surface, while also diffusing within the CIGS layer and strongly reducing the concentration of lighter alkali element sodium. These findings corroborate theoretical calculations published by another group, which predicted the segregation of potassium indium selenide (KInSe2) and rubidium indium selenide (RbInSe2) at CIGS surfaces under the used PDT conditions.

Iron oxides are among the most abundant materials on Earth, and yet there are some of their basic properties which are still not well-established. Here, we present temperature-dependent magnetic, X-ray, and neutron diffraction measurements refuting the current belief that the magnetic ordering temperature of ε-Fe2O3 is ∼500 K, i.e., well below that of other iron oxides such as hematite, magnetite, or maghemite. Upon heating from room temperature, the ε-Fe2O3 nanoparticles’ saturation magnetization undergoes a monotonic decrease while the coercivity and remanence sharply drop, virtually vanishing around ∼500 K. However, above that temperature the hysteresis loops present a nonlinear response with finite coercivity, making evident signs of ferrimagnetic order up to temperatures as high as 850 K (TN1). The neutron diffraction study confirms the presence of ferrimagnetic order well above 500 K with Pna'21' magnetic symmetry, but only involving two of the four Fe3+ sublattices which are ordered below TN2 ≈ 480 K, and with a reduced net ferromagnetic component, that vanishes at above 850 K. The results unambiguously show the presence of a high-temperature magnetic phase in ε-Fe2O3 with a critical temperature of TN1 ∼ 850 K. Importantly, this temperature is similar to the Curie point in other iron oxides, indicating comparable magnetic coupling strengths. The presence of diverse magnetic phases is further supported by the nonmonotonic evolution of the thermal expansion. The existence of a high-temperature ferrimagnetic phase in ε-Fe2O3 may open the door to further expand the working range of this multifunctional iron oxide.

The demonstration of reversible anionic redox in Li-rich layered oxides has revitalized the search for higher energy battery cathodes. To advance the fundamentals of this promising mechanism, we investigate herein the cationic–anionic redox processes in Li2Ru0.75Sn0.25O3—a model Li-rich layered cathode in which Ru (cationic) and O (anionic) are the only redox-active sites. We reveal its charge compensation mechanism and local structural evolutions by applying operando (and complementary ex situ) X-ray absorption spectroscopy (XAS). Among other local effects, the anionic-oxidation-driven distortion of the oxygen network around Ru atoms is thereby visualized. Oxidation of lattice oxygen is also directly proven via hard X-ray photoelectron spectroscopy (HAXPES). Furthermore, we demonstrate a spectroscopy-driven visualization of electrochemical reaction paths, which enabled us to neatly decouple the individual cationic–anionic dQ/dV contributions during cycling. We hence establish the redox and structural origins of all dQ/dV features and demonstrate the vital role of anionic redox in hysteresis and kinetics. These fundamental insights about Li-rich systems are crucial for improving the existing anionic-redox-based cathodes and evaluating the ones being discovered rapidly.

Advancement in explosive systems toward miniaturization and enhanced safety has prompted the development of primary explosives with powerful detonation performance and relatively low sensitivities. Energetic coordination polymers (ECPs) as a new type of energetic materials have attracted wide attention. However, regulating the energetic characters of ECPs and establishing the relationship between structure and energetic property remains great challenges. In this study, two isomorphic 2D π-stacked solvent-free coordination polymers, [M(N3)2(atrz)]n (M = Co 1, Cd 2; atrz = 4,4′-azo-1,2,4-triazole), were hydrothermally prepared and structurally characterized by X-ray diffraction. The two compounds exhibit reliable stabilities, remarkable positive enthalpies of formation, and prominent heats of detonation. The enthalpy of formation of 1 is 4.21 kJ·g–1, which is higher than those of all hitherto known primary explosives. Repulsive steric clashes between the sensitive azide ions in 1 and 2 influence the mechanical sensitivities deduced from the calculated noncovalent interaction domains. The two energetic π-stacked ECPs 1 and 2 can serve as candidates for primary explosives with an approved level of safety.

Single crystal semiconductors almost always exhibit better optoelectrical properties than their polycrystalline or amorphous counterparts. While three-dimensionally (3D) nanostructured semiconductor devices have been proposed for numerous applications, in the vast majority of reports, the semiconductor is polycrystalline or amorphous, greatly reducing the potential for advanced properties. While technologies for 3D structuring of semiconductors via use of a 3D template have advanced significantly, approaches for epitaxially growing nanostructured single crystal semiconductors within a template remain limited. Here, we demonstrate the epitaxial growth of 3D-structured ZnO through colloidal templates formed from 225 and 600 nm diameter colloidal particles via a low-temperature (∼80 °C) hydrothermal process using a flow reactor. The effects of the pH of the reaction solution as well as the additive used on the 3D epitaxy process are investigated. The optical and electrical properties of the epitaxially grown nanostructured ZnO are probed by reflectance, photoluminescence, and Hall effect measurements. It is found that the epitaxially grown nanostructured ZnO generally exhibits properties superior to those of polycrystalline ZnO. The demonstrated hydrothermal epitaxy process should be applicable to other chemical solution-based deposition techniques and help extend the range of materials that can be grown into a 3D nanostructured single-crystalline form.

n-Doping of P(BTP-DPP) with the organometallic dimer (RuCp*mes)2, processed through sequential casting, is reported. Maximum conductivities of 0.45 S cm–1 were achieved that are relatively high for n-type semiconducting polymers. Electron paramagnetic resonance spectroscopy, ultraviolet visible spectroscopy, and ultraviolet photoemission spectroscopy are consistent with the introduction of high carrier concentrations by sequential processing, leading to bipolaronic, or otherwise spin-paired carriers. P(BTP-DPP) has glassy ordering in thin films, observed using wide angle X-ray scattering, that allows efficient incorporation of the dopant as a function of processing condition. The changes in electrical conductivity as a function of the dopant concentration are proposed to occur by charge percolation through domains with a mixture of polaronic and bipolaronic carriers.

Noncovalent synthesis of stable heterostructures (graphene-BN, MoS2-graphene) of layered materials has been accomplished by a ternary host–guest complex as a heterocomplementary supramolecular motif. Besides being reversible, this supramolecular strategy to generate heterostructures may find uses in many situations.

Kinetic or thermodynamic control has been employed to guide the selective synthesis of conventional organic compounds, and it should be a powerful tool as well for accessing unusual inorganic nanocrystals, particularly when a series of members with similar chemical compositions and phase structures exist. Indeed, a comprehensive mapping of the energy barrier distribution of each nanocrystal in a predefined reaction system will enable not only the precise synthesis of nanocrystals with expected sizes, morphologies, phase structures, and ultimately functionalities, but also disclosure of the evolution details of nanocrystals from one structure to another. Using ScFx:Ln (x = 2.76, 3) series as a proof-of-concept, we have successfully mapped out the energy barriers that correspond to each of the ScFx:Ln nanocrystals, unraveled suitable temperatures for each type of nanocrystal formation, recorded their phase transition procedures, and also discovered the relationships of the products at each reaction stage. To testify how this approach allows one to tailor the structure-related optical properties, different lanthanide-doped ScFx nanocrystals were synthesized and a wide-range of luminescence fine-tuning was achieved, which not only showcases high quality of the nanocrystals, but also provides more candidates for various luminescence applications, especially when single-particle upconversion emission is required.

All inorganic cesium lead bromide (CsPbBr3) perovskite is a more stable alternative to methylammonium lead bromide (MAPbBr3) for designing high open-circuit voltage solar cells and display devices. Poor solubility of CsBr in organic solvents makes typical solution deposition methods difficult to adapt for constructing CsPbBr3 devices. Our layer-by-layer methodology, which makes use of CsPbBr3 quantum dot (QD) deposition followed by annealing, provides a convenient way to cast stable films of desired thickness. The transformation from QDs into bulk during thermal annealing arises from the resumption of nanoparticle growth and not from sintering as generally assumed. Additionally, a large loss of organic material during the annealing process is mainly from 1-octadecene left during the QD synthesis. Utilizing this deposition approach for perovskite photovoltaics is examined using typical planar architecture devices. Devices optimized to both QD spin-casting concentration and overall CsPbBr3 thickness produce champion devices that reach power conversion efficiencies of 5.5% with a Voc value of 1.4 V. The layered QD deposition demonstrates a controlled perovskite film architecture for developing efficient, high open-circuit photovoltaic devices.

The utilization of low bandgap copolymers has been considered as one of the most efficient ways to increase power conversion efficiencies (PCEs) of fullerene-based polymer solar cells (PSCs). However, an increase in the short-circuit current (JSC) value is usually counteracted by a decrease in the open-circuit voltage (VOC), which limits a further PCE enhancement of fullerene-based PSCs. As a result, nonfullerene acceptors with wide-range tunable energy levels are used as alternatives to the traditional fullerene acceptors to overcome the negative trade-off between the JSC and VOC. Here, a novel nonfullerene acceptor is developed by using an angular-shaped dithienonaphthalene flanked by electron-withdrawing 3-ethylrhodanine units via benzothiadiazole bridges. The obtained nonfullerene acceptor exhibits a high-lying lowest unoccupied molecular orbital level of −3.75 eV with enhanced absorption. In combination with a benchmark low bandgap copolymer (PTB7-Th), a high PCE of 9.51% with a large VOC of 1.08 V was achieved for the nonfullerene PSCs, demonstrating an extremely low energy loss of 0.50 eV, which is the lowest among all high-performance (PCE > 8%) polymer-based systems with similar optical bandgaps. The results demonstrate the bright future of our nonfullerene acceptor as an alternative to the fullerene derivatives for PSCs with large JSC and VOC values and improved device stability.

Colloidal nanorods with axial Si and Ge heterojunction segments were produced by solution–liquid–solid (SLS) growth using Sn as a seed metal and trisilane and diphenylgermane as Si and Ge reactants. The low solubility of Si and Ge in Sn helps to generate abrupt Si–Ge heterojunction interfaces. To control the composition of the nanorods, it was also necessary to limit an undesired side reaction between the Ge reaction byproduct tetraphenylgermane and trisilane. High-resolution transmission electron microscopy reveals that the Si–Ge interfaces are epitaxial, which gives rise to a significant amount of bond strain resulting in interfacial misfit dislocations that nucleate stacking faults in the nanorods.

The ability to topographically structure and fast controllably actuate hydrogel in two and three dimensions is the key for their promising applications in soft robots, microfluidic valves, cell and drug delivery, and artificial muscles. Inspired by evaporation-induced concentration differentiation phenomenon in the production process of beancurd sheet, we introduce a facile one-step evaporation process to create laminated layer/porous layer heterogeneous structure within graphene oxide-clay-poly(N-isopropylacrylamide) hydrogel in vertical direction and pattern the heterogeneous structure in lateral direction to form tunable, fast, and robust hydrogel actuators. The laminated layer/porous layer architecture is highly stable and robust without possibility of delamination. The evaporation-programmed heterogeneous structures tune thermoresponsive actuations from global bending/unbending for global heterogeneous structure to local bending/unbending and site-specific folding/unfolding for segment-patterned heterogeneous structure, then to directional bending/unbending and chiral twisting/untwisting for stripe-patterned heterogeneous structure. These actuations are instant and reversible without detectable fatigue after many cycles.

Ge1–xSnx nanorods (NRs) with a nominal Sn content of 28% have been prepared by a modified microwave-based approach at very low temperature (140 °C) with Sn as growth promoter. The observation of a Sn-enriched region at the nucleation site of NRs and the presence of the low-temperature α-Sn phase even at elevated temperatures support a template-assisted formation mechanism. The behavior of two distinct Ge1–xSnx compositions with a high Sn content of 17% and 28% upon thermal treatment has been studied and reveals segregation events occurring at elevated temperatures, but also demonstrates the temperature window of thermal stability. In situ transmission electron microscopy investigations revealed a diffusion of metallic Sn clusters through the Ge1–xSnx NRs at temperatures where the material composition changes drastically. These results are important for the explanation of distinct composition changes in Ge1–xSnx and the observation of solid diffusion combined with dissolution and redeposition of Ge1–ySny (x > y) exhibiting a reduced Sn content. Absence of metallic Sn results in increased temperature stability by ∼70 °C for Ge0.72Sn0.28 NRs and ∼60 °C for Ge0.83Sn0.17 nanowires (NWs). In addition, a composition-dependent direct bandgap of the Ge1–xSnx NRs and NWs with different composition is illustrated using Tauc plots.

Nanostructured palladium foams offer exciting potential for applications in diverse fields such as catalysts, fuel cells, and particularly hydrogen storage technologies. We have fabricated palladium nanowire foams using a cross-linking and freeze-drying technique. These foams have a tunable density down to 0.1% of the bulk, and a surface area-to-volume ratio of up to 1.54 × 106:1 m−1. They exhibit highly attractive characteristics for hydrogen storage, in terms of loading capacity, rate of absorption, and heat of absorption. The hydrogen absorption/desorption process is hysteretic in nature, accompanied by substantial lattice expansion/contraction as the foam converts between Pd and PdHx.

We report on the discovery of a quasi two-dimensional copper–bismuth nano sheet from ab initio calculations, which we call cubine. According to our predictions, single layers of cubine can be isolated from the recently reported high-pressure CuBi bulk material at an energetic cost of merely ≈20 meV/Å2, comparable to values to separate single layers of graphene from graphite. Our calculations suggest that cubine has remarkable electronic and electrochemical properties: It is a superconductor with a moderate electron–phonon coupling λ = 0.5, leading to Tc ≈ 1 K, and can be readily intercalated with lithium with a high diffusibility, rendering it a promising candidate material to boost the rate capacity of current electrodes in lithium-ion batteries.

Cu2ZnSnS4 (CZTS) is a very promising material for the absorber layer in sustainable thin-film solar cells. Its photovoltaic performance is currently limited by crystal structure disorder, which causes fluctuations in electrostatic potential that decrease open-circuit voltage. The origin of this disorder is still not fully understood. This work investigates five samples of CZTS over a range of compositions, fabricated by solid-state reaction. Their crystal structures are conclusively identified using high-resolution anomalous X-ray diffraction. Three of the samples display two distinct CZTS phases, evident in minute splitting of some diffraction peaks (by ∼0.02°) due to different c/a lattice parameter ratios. These are attributed to different composition types of CZTS, defined by different charge-neutral defect complexes. In addition to such types previously reported, two new types are proposed: G-type, in which [2CuSn3– + CuZn– + Cui+ + 3VS2+] defects are prevalent, and H-type, in which [3Si2– + VCu– + ZnCu+ + 2SnCu3+] defects are prevalent. In both cases, the defects probably do not form a single complex due to their large number. Above the order–disorder phase transition the two CZTS phases generally converge to a single phase. A mechanism of phase formation in CZTS is thus proposed. This is the first time CZTS crystal structures have been investigated with sufficiently high resolution to distinguish these different CZTS phases, thereby establishing polymorphic behavior in CZTS.

Low-temperature reduction of perovskite Tb0.5Ca0.5MnO3–x yields novel crystal-structured noncentrosymmetric compound Tb0.50Ca0.50Mn0.962.33+O2.37, which unusually crystallizes in cubic lattice I23 (a ∼ 15.27 Å) based on a 4ap × 4ap × 4ap expansion relative to the simple cubic perovskite unit cell. Rietveld refinements and HAADF-STEM images are used for the structure determination, revealing a rare-typed metal-anion coordination framework which consists of corner-shared tetrahedra and pyramids, and edge-shared bipyramids and octahedra. 2/64 B-site Mn-ordered vacancies are observed for the first time acting as the apex and body center of the I lattice in reduced systems. Room-temperature piezoelectricity is detected, with a quasistatic d33 value of ∼0.32 pC N–1 and inverse d33 value of ∼10.5 pm V–1. This phase primarily exhibits antiferromagnetic ordering below TN ∼ 70 K, with ferromagnetic responses resulted from spin-canting below 40 K. This work provides a new way toward synthesizing unconventional acentric materials, in the absence of second-order Jahn–Teller active “distortion centers”.

The donor–acceptor interface within molecular charge transfer (CT) solids plays a vital role in the hybridization of molecular orbitals to determine their carrier transport and electronic delocalization. In this study, we demonstrate molecular assembly-driven bilayer and crystalline solids, consisting of electron donor dibenzotetrathiafulvalene (DBTTF) and acceptor C60, in which interfacial engineering-induced CT degree control is a key parameter for tuning its optical, electronic, and magnetic performance. Compared to the DBTTF/C60 bilayer structure, the DBTTFC60 cocrystalline solids show a stronger degree of charge transfer for broad CT absorption and a large dielectric constant. In addition, the DBTTFC60 cocrystals exhibit distinct CT arrangement-driven anisotropic electron mobility and spin characteristics, which further enables the development of high-penetration and high-energy γ-ray photodetectors. The results presented in this paper provide a basis for the design and control of molecular charge transfer solids, which facilitates the integration of such materials into molecular electronics.