One-pot room-temperature synthesis of CsPbBr3/SiO2 nanocrystals with improved stability for white light-emitting diodes

The susceptibility to optical instability of perovskite nanocrystals (NCs) under ambient conditions is a serious hindrance for practical applications. The conventional SiO 2 coating method for enhancing stability suffered from long reaction times and complicated preparation procedures. In this study, a facile and convenient room-temperature one-pot approach was developed to fabricate CsPbBr 3 /SiO 2 NCs, which involves the addition of tetramethoxysilane (TMOS) in advance. Owing to surface passivation, the PLQY of the CsPbBr 3 /SiO 2 NCs increased to 90% from 70% of the primitive CsPbBr 3 NCs. The SiO 2 layer formed by the TMOS hydrolysis and condensation reactions also protect the CsPbBr 3 NCs from external environment stimuli. Compared with the pristine CsPbBr 3 NCs, the air stability, structural stability, polar solvent resistance, thermal stability, and UV resistance stability of the CsPbBr 3 /SiO 2 NCs are markedly enhanced. Also, the CsPbBr 3 /SiO 2 NCs can be used as green phosphors for white light-emitting diode (WLED), which exhibits a luminous efficiency of 40 lm/W.