Ultrastable and highly efficient CsPbBr_(3) composites achieved by dual-matrix encapsulation for display devices

Perovskite nanocrystals(NCs)with high stabilities and excellent optical perfor-mances are crucial for display applications.However,to date,perovskite emitters with both high photoluminescence(PL)quantum yield(PLQY)and high stabili-ties 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 encapsula-tion,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 environ-ment.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(85C),and strong blue light irradiation(350 mW cm2)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.