TY - JOUR
T1 - Iodine Electrochemistry Dictates Voltage-Induced Halide Segregation Thresholds in Mixed-Halide Perovskite Devices
AU - Xu, Zhaojian
AU - Kerner, Ross A.
AU - Berry, Joseph J.
AU - Rand, Barry P.
N1 - Funding Information:
The authors acknowledge funding for this work by the Department of the Navy, Office of Naval Research under ONR award number N00014‐21‐1‐2767. This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE‐AC36‐08GO28308. Funding for R.A.K. was provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Solar Energy Technologies Office (SETO) project “De‐risking Halide Perovskite Solar Cells” program (DE‐FOA‐0000990). The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.The authors acknowledge the use of Princeton's Imaging and Analysis Center (IAC), which is partially supported by the Princeton Center for Complex Materials (PCCM), a National Science Foundation (NSF) Materials Research Science and Engineering Center (MRSEC; DMR‐2011750).
Publisher Copyright:
© 2022 National Renewable Energy Laboratory. Advanced Functional Materials published by Wiley-VCH GmbH.
PY - 2022/8/15
Y1 - 2022/8/15
N2 - Owing to straightforward stoichiometry–bandgap tunability, mixed-halide perovskites are ideal for many optoelectronic devices. However, unwanted halide segregation under operational conditions, including light illumination and voltage bias, restricts practical use. Additionally, the origin of voltage-induced halide segregation is still unclear. Herein, a systematic voltage threshold study in mixed bromide/iodide perovskite devices is performed and leads to observation of three distinct voltage thresholds corresponding to the doping of the hole transport material (0.7 ± 0.1 V), halide segregation (0.95 ± 0.05 V), and degradation (1.15 ± 0.05 V) for an optically stable mixed-halide perovskite composition with a low bromide content (10%). These empirical threshold voltages are minimally affected by composition until very Br-rich compositions, which reveals the dominant role of iodide/triiodide/iodine electrochemistry in voltage-induced Br/I phase separation and transport layer doping reactions in halide perovskite devices.
AB - Owing to straightforward stoichiometry–bandgap tunability, mixed-halide perovskites are ideal for many optoelectronic devices. However, unwanted halide segregation under operational conditions, including light illumination and voltage bias, restricts practical use. Additionally, the origin of voltage-induced halide segregation is still unclear. Herein, a systematic voltage threshold study in mixed bromide/iodide perovskite devices is performed and leads to observation of three distinct voltage thresholds corresponding to the doping of the hole transport material (0.7 ± 0.1 V), halide segregation (0.95 ± 0.05 V), and degradation (1.15 ± 0.05 V) for an optically stable mixed-halide perovskite composition with a low bromide content (10%). These empirical threshold voltages are minimally affected by composition until very Br-rich compositions, which reveals the dominant role of iodide/triiodide/iodine electrochemistry in voltage-induced Br/I phase separation and transport layer doping reactions in halide perovskite devices.
KW - mixed-halide perovskites
KW - voltage thresholds
KW - voltage-induced halide segregation
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U2 - 10.1002/adfm.202203432
DO - 10.1002/adfm.202203432
M3 - Article
AN - SCOPUS:85132018132
SN - 1616-301X
VL - 32
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 33
M1 - 2203432
ER -