Solution-processed approach to highly luminescent trigonal Cs4PbBr6 nanodisks and their underlying shape evolution

All-inorganic cesium lead halide, a kind of promising semiconductor materials with fantastic properties for photoelectronic and photovoltaic applications, emerged recently. Herein, we report new strategies for synthesizing of trigonal Cs4PbBr6 nanodisks (NDs), which are also of ultrahigh luminescent (PLQY reached 85%). The key points to the high-yield synthesis of perovskite NDs are the elevated concentration of Cs precursor and proper temperature. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the Cs4PbBr6 NDs are built due to a selectivity of the ligands capping the different facets of a seed. Particularly, we find that by using cesium acetate as cesium source instead of cesium carbonate, the geometric construction of NDs is more defined, which indicates that the extra anions have a substantial effect on the perovskite crystal growth kinetics and their morphologies. Our work presents a new opportunity for better understanding the effect of composition, surface chemistry and intrinsic efficient luminescence in perovskite nanoparticles.