Unraveling the Degradation and Air-Induced Healing Mechanisms of Halide Perovskites under Proton Irradiation.

As exceptional potential candidates for future-generation space photovoltaics, perovskite solar cells (PSCs) have been proven to be radiation-tolerant and recoverable under proton irradiation. Nevertheless, a key point, the influence of the atmosphere, has often been overlooked in ground-based irradiation experiments. Here, the atmosphere-dependent radiation tolerance and healing of perovskite materials under MeV proton irradiation are demonstrated by utilizing in situ electrical characterizations. Significant degradation is observed in the electrical properties after irradiation, which can hardly be recovered in vacuum but can quickly be recovered to approach the initial state in the presence of oxygen. The atmosphere-dependent behaviors are related to the proton-induced iodine vacancies in perovskites through in situ and ex situ characterizations. Ultimately, the underlying degradation and healing mechanisms are unraveled by using simulation. This work aims to provide a more comprehensive assessment of radiation tolerance of perovskites. These results are of great significance for designing and optimizing PSCs for future space applications including rapid screening, encapsulation, and radiation hardening.