In situ preparation of water-stable SiO2@mSiO2/CsPbBr3 and its application in WLED

Recently, all-inorganic perovskites as photoluminescent materials have attracted significant attention in the field of light-emitting diodes. However, their instability towards UV light, high temperature, and water has impeded widespread commercial applications. We propose a facile strategy for synthesizing CSSM-CPB by encapsulating perovskite CsPbBr3 (CPB) into the channels of core-shell silica microspheres (CSSM). Subsequently, the channels of CSSM-CPB were sealed with octadecyltrichlorosilane (ODS). Consequently, the stability of CSSM-CPB to UV light, high temperature, and water significantly improved. Notably, CSSM-CPB retains a high fluorescence emission intensity even after immersion in water for 30 days. Furthermore, the photoluminescence quantum yield of CSSM-CPB reaches 68%, compared to just 30% for discrete CPB. A CSSM-CPB-WLED was also developed, exhibiting a color temperature (Tc) of 5869 K, Commission Internationale de l'Éclairage (CIE) color coordinates of (0.34, 0.34), a luminous efficiency of 86.31 lm W−1, and a color gamut overlap with the NTSC space of approximately 121.1%. These results indicate a significant enhancement over CPB-WLED, suggesting that the stability of CPB can be improved through silica encapsulation and hydrophobic material sealing. This approach has potential for commercial application in display devices requiring high stability.