Halogen Redox Shuttle Explains Voltage-Induced Halide Redistribution in Mixed-Halide Perovskite Devices
- Zhaojian XuZhaojian XuDepartment of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey08544, United StatesMore by Zhaojian Xu
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- Ross A. KernerRoss A. KernerNational Renewable Energy Laboratory, Golden, Colorado80401, United StatesMore by Ross A. Kerner
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- Steven P. HarveySteven P. HarveyNational Renewable Energy Laboratory, Golden, Colorado80401, United StatesMore by Steven P. Harvey
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- Kai Zhu
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- Joseph J. BerryJoseph J. BerryNational Renewable Energy Laboratory, Golden, Colorado80401, United StatesRenewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado80309, United StatesDepartment of Physics, University of Colorado Boulder, Boulder, Colorado80309, United StatesMore by Joseph J. Berry
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- Barry P. Rand*Barry P. Rand*Email for B.P.R.: [email protected]Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey08544, United StatesAndlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey08544, United StatesMore by Barry P. Rand
Abstract
Voltage-induced halide segregation greatly limits the optoelectronic applications of mixed-halide perovskite devices, but a mechanistic explanation behind this phenomenon remains unclear. In this work, we use electron microscopy and elemental mapping to directly measure the halide redistribution in mixed-halide perovskite solar cells with quasi-ion-impermeable contact layers under different bias polarities to find iodide and bromide accumulation at the cathode and anode, respectively. This is consistent with a mechanism based on preferential iodide oxidation at the anode, leading to unbalanced , , and fluxes. Importantly, switching the anode from “inert” Au to “active” Ag prevents segregation because Ag oxidation precludes the oxidation of lattice iodide, which suggests employing redox-active additives as a general strategy to suppress halide segregation. Overall, these results show that halide perovskite devices operate as solid-state electrochemical cells when threshold voltages are exceeded, providing fresh insight to understand the impacts of voltage bias on halide perovskite devices.
Cited By
This article is cited by 1 publications.
- Zhaojian Xu, Daniel D. Astridge, Ross A. Kerner, Xinjue Zhong, Junnan Hu, Jisu Hong, Jesse A. Wisch, Kai Zhu, Joseph J. Berry, Antoine Kahn, Alan Sellinger, Barry P. Rand. Origins of Photoluminescence Instabilities at Halide Perovskite/Organic Hole Transport Layer Interfaces. Journal of the American Chemical Society 2023, 145 (21) , 11846-11858. https://doi.org/10.1021/jacs.3c03539