Thermal stability of CsPbBr3 perovskite as revealed by in situ transmission electron microscopy

The thermal stability of all-inorganic halide perovskites is their key advantage over organic/hybrid halide perovskites. Here, in situ high-resolution transmission electron microscopy (HRTEM) was used to directly investigate crystallography dynamics of a CsPbBr3 perovskite at high temperature (up to 690 K). In high vacuum TEM conditions (∼10−5 Pa), CsPbBr3 nanocrystals possessed superb stability at temperatures below 690 K. By sealing the crystals in amorphous carbon, their melting and solidification processes were directly observed at temperatures of 840 K and 838 K, respectively. This study should be valuable for future perovskite-containing solar cells, lasers, light-emitting diodes, and photodetectors working at high temperatures.