Phase engineering of inorganic halide Cs–Pb–Br perovskites for advanced energy conversion

Abstract

All-inorganic metal halide perovskites have been actively investigated as promising energy-converting materials for abundant applications owing to their excellent electronic and optical properties. Three-dimensional (3D) CsPbBr₃, two-dimensional (2D) CsPb₂Br_5, and zero-dimensional (0D) Cs₄PbBr₆ obtained by Cs–Pb–Br dimensional engineering at the molecular level open a new avenue for the development and application of metal halide perovskites. A continuously increasing number of studies are devoted to the phase transitions of 3D CsPbBr₃, 2D CsPb₂Br₅ and 0D Cs₄PbBr₆ to improve the stability and electronic and optical properties of metal halide perovskites by forming multi-phase perovskite structures. Herein, recent advances in the phase transitions of these three materials are discussed systematically. The processes occurring during the reversible phase transitions of 3D CsPbBr₃, 2D CsPb₂Br₅ and 0D Cs₄PbBr₆ are elaborated, and their reaction mechanisms are described. In addition, the latest applications of all-inorganic metal halide perovskites in photoelectric, electro-optical, and all-optical conversion processes are summarized. Finally, future research directions related to the development of inorganic metal halide perovskites for these applications are outlined. In summary, the phase transitions of all-inorganic perovskites provide attractive opportunities for multi-field applications.