Iodine electrochemistry and halide perovskite degradation

With certified photovoltaic efficiencies of metal halide perovskite solar cells currently approaching 27%, and perovskite-based light emitting diode external quantum efficiency beyond 30%, focusing attention on device degradation and their exact chemical mechanisms is critical. We have recently uncovered evidence of numerous degradation mechanisms – interactions with hole transport media, mixed halide phase separation, contact corrosion, and A-site deprotonation – which all source from iodine electrochemistry. We will discuss these issues and their implications for halide perovskite devices.