In-situ synthesis of highly stable CsPbBr3/PbBrF composite nanocrystals induced by Hydrofluoric acid

All inorganic lead cesium halide perovskites (CsPbX3, X = Cl, Br, I) nanocrystals (NCs) are supposed to be promising luminescent-converting materials for next-generation displays, on account of their excellent optical and photoelectric properties, facile synthesis, and low cost. However, the inherent poor stability hinders their implementation in practical applications. Here, we present a simple cooperative strategy for the synthesis of stable green perovskite composite luminophore powders. In a typical cooperative process, HF leads to the formation of PbBrF framework in which the green-emitting CsPbBr3 NCs that are transformed from the non-emitting precursors CsPb2Br5 NCs by hydration, are simultaneously embedded in. The obtained CsPbBr3/PbBrF composites NCs maintain photoluminescence quantum yield (∼ 30%) and narrow band emission (∼ 22 nm). Additionally, benefiting from the PbBrF framework with good thermal diffusivity and stability, CsPbBr3/PbBrF composite NCs show excellent stability to heat, radiation, and polar solvents, which can be used as promising green luminescent-converting materials in the next-generation displays.