In Situ Growth of CsPbBr₃ Perovskite Nanocrystals in Lead‐Based Matrix toward Significantly Enhanced Water/Photo Stabilities

Abstract Perovskite nanocrystals (NCs) are considered as the next‐generation platforms for optoelectronic applications, but their poor stability greatly restricts their development. Here, we present a facile composite strategy to synthesize highly stable CsPbBr₃/Pb‐MA composite by in situ embedding the CsPbBr₃ NCs in a C₁₆H₁₄Br₂O₆Pb₂ (Pb‐MA) organometallic compound (MOC). The CsPbBr₃/Pb‐MA composite powders show intense green emission at 519 nm, with a photoluminescence quantum yield of about 48.5% and a full width at half‐maximum of about 17 nm. More interestingly, benefitted from the protection of MOC, the CsPbBr₃/Pb‐MA composites can maintain 43% and 83% of initial intensity after being illuminated under blue light for 36 h and being immersed in water for 192 h, respectively. Compared to the original CsPbBr₃ NCs, the light/water stability of CsPbBr₃/Pb‐MA composites is enhanced by about 40 and 700 times (the PL intensities maintain at about 60% of the initial one), respectively. As a proof‐of‐concept, the as‐fabricated devices exhibit a wide color gamut, 97.7% and 98.2% of Rec. 2020 for white light‐emitting diodes and laser diodes, respectively. These findings demonstrate that the combination of MOC and perovskite NCs is an optimized strategy for the exploitation of high‐performance perovskite composites for their future optoelectronic applications.