Melting and Crystallization Features of CsPbBr3 Perovskite

The all-inorganic perovskite cesium lead bromide (CsPbBr3) has attracted considerable attention as a promising material for optoelectronics and high-energy radiation detectors. In order to obtain a bulk single crystal from a melt, it is crucial to understand the peculiarities of melting and crystallization processes. Here, the solid-liquid and liquid-solid phase transitions were studied by differential thermal analysis at different heating/cooling rates (0.1, 1, 3, 5, and 10 degrees C/min). A two-stage melting mechanism of CsPbBr3 perovskite was proposed. The critical maximal sample temperature (Tcritical) was determined for each heating rate. If the sample was heated to a temperature below Tcritical, the crystallization occurred at a temperature higher than the melting point. Contrarily, if the sample was heated to a temperature higher than this critical value, the melt crystallization occurred with supercooling. We believe that such crystallization features are closely related to the melt structure, which changes during the sample heating. The activation energies of melting and crystallization processes of CsPbBr3 were determined to be 1846 and 1940 kJ/mol, respectively. For the first time, this study demonstrates the impact of heating and cooling conditions on the melting and crystallization processes of the bulk CsPbBr3. It is significant for gaining a fundamental understanding of the crystal growth and fabrication of high-quality monocrystalline materials.