Gamma‐Ray Radiation Stability of Mixed‐Cation Lead Mixed‐Halide Perovskite Single Crystals

Abstract Organic–inorganic hybrid lead halide perovskites have shown extraordinary potentials in space photovoltaic technology and high‐energy‐rays detection but their practical application still faces the bottleneck of radiation‐induced instability. Specifically, gamma‐ray radiation hardness is a main concern due to the highest penetrability and difficulty in stopping of gamma‐photons. However, the gamma‐ray radiation stability of perovskites remains controversial. Herein, stability of mixed‐cation lead mixed‐halide FA_0.95Cs_0.05PbI_2.7Br_0.3 single crystals under ⁶⁰Co gamma‐ray radiation of different doses is investigated by tracking the evolution of structural, optical, and photophysical properties. Importantly, they show excellent stability to humidity and heat, eliminating the potential influence of moisture and temperature upon evaluating their gamma‐ray radiation stability. FA_0.95Cs_0.05PbI_2.7Br_0.3 single crystals are found stable with an accumulated dose lower than 200 krad and the performance of the irradiated perovskite photodetector could almost completely self‐heal after aging in dark. Perovskite decomposition occurs when the radiation dose is increased to 400 krad or even higher. These phenomena are explained by the synergistic effect between defects generation and lattice reparation caused by ion redistribution during gamma‐ray radiation. These results provide guidance for their practical application in space photovoltaic technology and gamma‐ray detectors.