Ultrastable and highly efficient CsPbBr 3 composites achieved by dual‐matrix encapsulation for display devices

Abstract Perovskite nanocrystals (NCs) with high stabilities and excellent optical performances are crucial for display applications. However, to date, perovskite emitters with both high photoluminescence (PL) quantum yield (PLQY) and high stabilities under harsh synergistic humidity–heat–light aging conditions have not been reported. The promising high‐temperature solid‐state sintering with single oxide matrices cannot ensure high PLQY and synergistic aging stabilities of perovskites. Herein, both the PLQY and overall (thermal, moisture, and photo) stabilities of all‐inorganic perovskite (CsPbBr 3 ) NCs are improved by dual‐matrix encapsulation, which is accomplished by in situ crystallization of CsPbBr 3 @Cs 4 PbBr 6 nanocomposites in silica molecular sieve (MS) templates via advanced solid‐state synthesis a using precisely controlled molar ratio of precursor components and cooling rates. The Cs 4 PbBr 6 matrix effectively passivates the surfaces of CsPbBr 3 NCs, and the MS matrix insulates CsPbBr 3 @Cs 4 PbBr 6 from the external environment. The resulting CsPbBr 3 @Cs 4 PbBr 6 /MS composites exhibit the highest PLQY (>90%) among those of the solid‐state perovskite NCs and significant stabilities against water, heat, and blue light irradiation, maintaining more than 80% of their initial PL intensities after being aged for 1000 h under synergistic high‐humidity (85%), high‐temperature (85°C), and strong blue light irradiation (350 mW cm −2 ) conditions. To the best of our knowledge, these CsPbBr 3 @Cs 4 PbBr 6 /MS composites represent the most stable perovskite emitters under synergistic humidity–heat–light aging conditions. The liquid crystal display backlight module fabricated using these stable composites demonstrates a wide color gamut of 131% of the National Television Standards Committee standard. We speculate that this dual‐matrix encapsulation can be used for industrial mass production. image