Facile Method for the Controllable Synthesis of Cs _xPb _yBr _z-Based Perovskites

We report a facile method to realize the selective synthesis of Cs _xPb _yBr _z-based perovskites, including CsPbBr₃, Cs₄PbBr₆ and CsPb₂Br₅. The use of an appropriate amount of N, N-dimethylformamide (DMF) solvent is experimentally determined to play a critical role in the controlled formation of various perovskite products. With continuously increasing DMF concentration, first CsPbBr₃ nanocrystals with tunable size can be achieved, and then the production of Cs₄PbBr₆ and CsPb₂Br₅ perovskite analogues is successively realized. Our findings present a novel path for the controlled synthesis of other perovskite analogues for specific applications.