Mesoporous Silica-Coated CsPbX3 Nanocrystals with High Stability and Ion-Exchange Resistance for Bright White-Emitting Displays

All-inorganic metal halide perovskite (CsPbX3) nanocrystals (NCs) have attracted much attention due to their excellent photoelectric properties. However, CsPbX3 NCs are easily affected by polar solvents because of their ionic crystal nature, which led to luminescence quenching. In this paper, mesoporous silica nanoparticles (MSNs) were used as carriers to anchor CsPbX3 NCs for effectively improving the resistance of CsPbX3 NCs in polar solvents. CsPbX3@MSN composites were created via a sol–gel-assisted ligand exchanging process. The photoluminescence (PL) intensity of the CsPbX3@MSNs composite still maintained more than 50% of their initial value after 60 min of treatment with water and ethanol. The mesoporous structures of SiO2 spheres facilitate efficient coupling of CsPbX3 NCs to improve the stability and decrease surface defects, resulting in high PL quantum yield. CsPbX3@MSN composites have unique advantages for white-light-emitting diodes (LEDs) as solid-state luminescent materials. White LED devices were fabricated using CsPbX3@MSN composites as the solid-state light-emitting conversion layer. The color temperature was 6838 K, and the luminous efficiency was 8.9 lm/W. Its coincidence degree with the gamut space specified by NTSC 1953 is 135%, and the coincidence degree with the gamut space specified by ITU-R B.T. 2020 (Rec. 2020) is 95%.