Role of Ion-Migration Kinetics on the Stability of Perovskite Halides

Metal halide perovskites have emerged as an exciting class of outstanding photosensitive semiconductor materials for various applications, including solar cells, light-emitting diodes, photodetectors, lasers, and X-ray scintillators. However, their application is significantly hindered by stability issues. To enhance the stability of metal halide perovskites, many strategies have been introduced, such as alloying, dimensionality reduction, and the introduction of ionic additives. Despite these efforts, the electronic origins of instability, particularly regarding the interactions between the elements in the chemical composition of perovskites and the specific ion migrations that affect their stability, remain elusive. In this work, we systematically explore the roles of ion migration barriers in the stability of both single and double perovskite halides. We find that the decomposition temperature of the perovskites is controlled by the average halogen migration barriers, and the phase transition from cubic to tetragonal is correlated with the cation-anion migration barrier differences. Additionally, we reveal the electronic origins of these ion migration barriers.