Ceramic-like stable CsPbBr₃ nanocrystals encapsulated in silica derived from molecular sieve templates

Achieving good stability while maintaining excellent properties is one of the main challenges for enhancing the competitiveness of luminescent perovskite CsPbX₃ (X=Cl, Br, I) nanocrystals (NCs). Here, we propose a facile strategy to synthesize ceramic-like stable and highly luminescent CsPbBr₃ NCs by encapsulating them into silica derived from molecular sieve templates at high temperature (600-900 ^oC). The obtained CsPbBr₃-SiO₂ powders not only show high photoluminescence quantum yield (~71%), but also show an exceptional stability comparable to the ceramic Sr₂SiO₄:Eu²⁺ green phosphor. They can maintain 100% of their photoluminescence value under illumination on blue light-emitting diodes (LEDs) chips (20 mA, 2.7 V) for 1000 h, and can also survive in a harsh hydrochloric acid aqueous solution (1 M) for 50 days. We believe that the above robust stabilities will significantly enhance the potential of perovskite CsPbX₃ NCs to be practically applied in LEDs and backlight displays.