Spatial and chemical confined ultra-small CsPbBr₃ perovskites in dendritic mesoporous silica nanospheres with enhanced stability

Cesium lead halide-based perovskite (CsPbX₃, X = Cl, Br, I) nanoparticles (NPs) have received considerable attention for their outstanding photophysical properties and promising applications in optoelectronic devices. However, the optoelectronic performance of CsPbX₃ NPs synthesized by most of present strategies are susceptible to external factors when exposed in atmosphere. Herein, benefiting from the unique open 3D porous architecture of dendritic mesoporous silica nanospheres (DMSNs) with cage-like spherical nanopores, highly dispersed and pure cubic CsPbX₃ NPs were successfully immobilized onto the mesoporous networks. A strategy of combining chemical anchoring and spatial isolation is designed for the one-pot synthesis of CsPbX₃ NPs. These as-fabricated CsPbX₃@HA-DMSNs exhibit excellent luminescence property (tunable emission color and high quantum yield (QY reached a maximum of 55%)) and enhanced stability (especially for the water resistance capacity). The photoluminescence (PL) was sustained without any distinct change after 100 d storage under ambient conditions, even 90% PL intensity was maintained after continuous UV irradiation for 45 h and no obvious PL reduction was observed when soaked in water for 7 h. Most importantly, the resulting CsPbX₃@HA-DMSNs could be easily purified by filtration without aggregation and easy to scale up production compared with the conventional solution-phase mediated synthesis, which provides an alternative for the effective fabrication of perovskite-based devices, for example, here, the white light emitting devices (LEDs).