Unravelling the Material Composition Effects on the Gamma Ray Stability of Lead Halide Perovskite Solar Cells: MAPbI3 Breaks the Records.

In this work, we report a comparative study of the gamma ray stability of perovskite solar cells based on a series of perovskite absorbers including MAPbI3 (MA = methylammonium), MAPbBr3, Cs0.15FA0.85PbI3 (FA = formamidinim), Cs0.1MA0.15FA0.75PbI3, CsPbI3, and CsPbBr3. We reveal that the composition of the perovskite material strongly affects the radiation stability of the solar cells. In particular, solar cells based on the MAPbI3 were found to be the most resistant to gamma rays since this perovskite undergoes rapid self-healing due to the special gas-phase chemistry analyzed with ab initio calculations. The fact that the solar cells based on MAPbI3 can withstand 1000 kRad gamma ray dose without any noticeable degradation of the photovoltaic properties) is particularly exciting and shifts the paradigm of research in this field towards designing more dynamic rather than intrinsically robust (e.g. inorganic) materials.