Dimensionality Control of Inorganic and Hybrid Perovskite Nanocrystals by Reaction Temperature: From No-Confinement to 3D and 1D Quantum Confinement

This work focuses on the systematic investigation of the shape, size, and composition-controlled synthesis of perovskite nanocrystals (NCs) under inert gas-free conditions and using pre-synthesized precursor stock solutions. In the case of CsPbBr3 NCs, we find that the lowering of reaction temperature from similar to 175 to 100 degrees C initially leads to a change of morphology from bulk-like 3D nanocubes to 0D nanocubes with 3D-quantum confinement, while at temperatures below 100 degrees C the reaction yields 2D nanoplatelets (NPls) with 1D-quantum confinement. However, to our surprise, at higher temperatures (similar to 215 degrees C), the reaction yields CsPbBr3 hexapod NCs, which have been rarely reported. The synthesis is scalable, and their halide composition is tunable by simply using different combinations of precursor solutions. The versatility of the synthesis is demonstrated by applying it to relatively less explored shape-controlled synthesis of FAPbBr(3) NCs. Despite the synthesis carried out in the air, both the inorganic and hybrid perovskite NCs exhibit nearly-narrow emission without applying any size-selective separation, and it is precisely tunable by controlling the reaction temperature.