Influence of halide mixing on thermal and photochemical stability of hybrid perovskites: XPS studies

The effect of I^–/Cl^–and I^–/Br^–mixing on the thermal and photochemical degradation of organometallic perovskite MeNH₃PbI₃ (MAPbI₃) was studied by X-ray photoelectron spectroscopy, which revealed the opportunity to essentially increase the photo and thermal stabilities of the material depending on the level and position of halide-mixing. The largest positive effect was observed for the small concentration of chloride substituent (MAPbI_2.7Cl_0.3), while the full halide substitution (MAPbBr₃) had a negative effect on the stability of hybrid perovskite.