Light Soaking Phenomena in Organic–Inorganic Mixed Halide Perovskite Single Crystals

Abstract

Recently, organic–inorganic mixed halide perovskite (MAPbX3; MA = CH3NH3+, X = Cl–, Br–, or I–) single crystals with low defect densities have been highlighted as candidate materials for high-efficiency photovoltaics and optoelectronics. Here we report the optical and structural investigations of mixed halide perovskite (MAPbBr3–xIx) single crystals. Mixed halide perovskite single crystals showed strong light soaking phenomena with light illumination conditions that were correlated to the trapping and detrapping events from defect sites. By systematic investigation with optical analysis, we found that the pseudocubic phase of mixed halide perovskites generates light soaking phenomena. These results indicate that photoinduced changes are related to the existence of multiple phases or halide migrations.