Ultra-stable CsPbBr3 nanocrystals encapsulated in mesoporous silica KIT-6 for LED applications

Metal halide perovskite nanocrystals (NCs) with strong absorption, high photoluminescence quantum yield (PL QY) and narrow bandwidth have shown great potential for display applications. However, their poor stability hinders their long-term device applications. Herein, we encapsulate CsPbBr3 NCs in closed-hole mesoporous silica KIT-6 through the facile high temperature solid reaction method. The obtained CsPbBr3@KIT-6 composites exhibit a high PL QY of 64% and a narrow bandwidth of 24 nm. Particularly, the collapsed mesoporous silica can protect the CsPbBr3 NCs from the impact of water or light irradiation. For instance, the PL QY of the NCs maintains 90% of the initial value after being immersed in water for 30 days. Ultimately, white-light-emitting diode (WLED) with a wide color gamut of 126.5% National Television System Committee (NTSC) standard was fabricated by packaging green-emitting CsPbBr3@KIT-6 powders, K2SiF6: Mn4+ red phosphor and blue diode chip. The WLED maintained 88% of its initial luminous efficacy after 30 days of operation, exhibiting good device stability.