Ligand-Mediated Synthesis of Shape-Controlled Cesium Lead Halide Perovskite Nanocrystals via Reprecipitation Process at Room Temperature

Colloidal nanocrystals of fully inorganic cesium lead halide (CsPbX3, X = Cl, Br, I, or combinations thereof) perovskites have attracted much attention for photonic and optoelectronic applications. Herein, we demonstrate a facile room-temperature (e.g., 25 °C), ligand-mediated reprecipitation strategy for systematically manipulating the shape of CsPbX3 colloidal nanocrystals, such as spherical quantum dots, nanocubes, nanorods, and nanoplatelets. The colloidal spherical quantum dots of CsPbX3 were synthesized with photoluminescence (PL) quantum yield values up to >80%, and the corresponding PL emission peaks covering the visible range from 380 to 693 nm. Besides spherical quantum dots, the shape of CsPbX3 nanocrystals could be engineered into nanocubes, one-dimensional nanorods, and two-dimensional few-unit-cell-thick nanoplatelets with well-defined morphology by choosing different organic acid and amine ligands via the reprecipitation process. The shape-dependent PL decay lifetimes have been determined t...