Synthesis of Ultrathin Perovskite Nanowires via a Postsynthetic Transformation Reaction of Zero-Dimensional Perovskite Nanocrystals

The synthesis of lead-halide perovskite (LHP) thin nanowires (NWs) has been a challenging task that requires delicate control of nanocrystal (NC) nucleation and growth processes. Herein, we present a novel synthesis of ultrathin CsPbBr3 NWs through a postsynthetic transformation reaction starting from zero-dimensional Cs4PbBr6 perovskite NCs. The synthesized CsPbBr3 NWs averaged 2.5 nm in width and tens of micrometers in length, showing a blue photoluminescence with an emission quantum yield of 15.2%. Mechanistic studies show that the morphology of the final transformation product is determined by the chain length of the capping ligand and thus the formed template structure of the PbBr2-ligand intermediates. We demonstrate that this reaction scheme can be applied to the synthesis of CsPbI3 NCs with a low-dimensional morphology. Our study provides not only a new route to achieve ultrathin LHP NWs postsynthesis but also insights into the template-related nucleation and growth mechanisms of LHP NCs.