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-cellthick?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 to be several to tens to hundreds of?nanoseconds. Our method provides a facile and versatile route to rationally control the shape of the CsPbX3 perovskites?nanocrystals, which will create opportunities for applications such as displays, lasing, light-emitting diodes, solar?concentrators, and photon detection.
Shibin Sun,Dan Yuan,Yuan Xu,Aifei Wang,and Zhengtao Deng.