Iodine Electrochemistry Dictates Voltage‐Induced Halide Segregation Thresholds in Mixed‐Halide Perovskite Devices
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 17, 2022
- Source ID
- 10.1002/adfm.202203432
Entities
People
- Barry P Rand
- Joseph J. Berry
- Ross A. Kerner
- Zhaojian Xu
Organizations
- National Renewable Energy Laboratory
- National Science Foundation
- Office of Energy Efficiency and Renewable Energy
- Office of Naval Research
- Princeton University
- Solar Energy Technologies Office
- United States Department of Energy
- University of Colorado Boulder