Ion Migration in Metal Halide Perovskites

Abstract

Metal halide perovskites are promising photovoltaic materials, but they still have some issues that need to be solved. Hys-teresis is a phenomenon that strongly is correlated with ion migration; thus, a fast, easy, and low-temperature method for measuring ion migration is required. Through selective blocking, ion migration can be measured separately, apart from elec-tron migration. In this study, ion migration in metal halide perovskites was measured using a vertical device. At different temperatures, ionic activation energies were obtained for a range of perovskite compositions such as MAPbI, FAPbI, CsP-bI , and MAPbBr . By comparing the measured ionic activation energies with the theoretical values, we conclude that among other possibilities, I is the migrating ion in MAPbI , FAPbI, CsPbI and Br is the migrating in MAPbBr .