Changing the Dimensionality of Cesium Lead Bromide Nanocrystals by Reversible Postsynthesis Transformations with Amines

Researchers report how, starting from CsPbBr3 nanocrystals (NCs), it is possible to obtain 0D Cs4PbBr6 NCs by the simple addition of different amines at room temperature. This transformation is triggered by the extraction of PbBr2 from the 3D CsPbX3 perovskite NCs operated by the excess amines, driven by the formation of complexes of amines with PbBr2. They also show that this process can also be carried out on dried NC films upon their exposure to vapors of a volatile alkylamine, such as butylamine (BuAm).