Facile Method for the Controllable Synthesis of CsxPbyBrz-Based Perovskites

We report a facile method to realize the selective synthesis of CsxPbyBrz-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.