Scalable room-temperature synthesis of plum-pudding-like Cs4PbBr6/CsPbBr3 microcrystals exhibiting excellent photoluminescence

All-inorganic halide perovskites have attracted significant attention because of their excellent photoelectric performance. However, several remaining challenges, including large-scale synthesis, strict limitations on the experimental conditions, and material stability, limit their practical application. In this study, we propose a simple ligand-assisted supersaturated recrystallization (LASR) procedure in order to prepare perovskite-related plum-pudding-like Cs4PbBr6/CsPbBr3 microcrystals (MCs) on a large scale and at room temperature. The LASR approach was proved to rely on the selection of an appropriate antisolvent. The synthesized Cs4PbBr6/CsPbBr3 MCs exhibit strong green emission at 520 nm with a narrow full-width at half-maximum (FWHM) value of 20 nm originating from the CsPbBr3 nanocrystals (NCs) embedded in the Cs4PbBr6 MCs. Additionally, the environmental stability experiment showed ∼20% PL intensity loss after storage under ambient conditions with 50% relative humidity (RH) for 2 months.