Ultrastable Perovskite–Zeolite Composite Enabled by Encapsulation and In Situ Passivation

Metal halide perovskites have been widely applied in optoelectronic fields, but their poor stability hinders their actual applications. A perovskite–zeolite composite was synthesized via in situ growth in air from aluminophosphate AlPO‐5 zeolite crystals and perovskite nanocrystals. The zeolite matrix provides quantum confinement for perovskite nanocrystals, achieving efficient green emission, and it passivates the defects of perovskite by H‐bonding interaction, which leads to a longer lifetime compared to bulk perovskite film. Furthermore, the AlPO‐5 zeolite also acts as a protection shield and enables ultrahigh stability of perovskite nanocrystals under 150 °C heat stress, under a 15‐month long‐term ambient exposure, and even in water for more than 2 weeks, respectively. The strategy of in situ passivation and encapsulation for the perovskite@AlPO‐5 composite was amenable to a range of perovskites, from MA‐ to Cs‐based perovskites. Benefiting from high stability and photoluminescence performance, the composite exhibits great potential to be virtually applied in light‐emitting diodes (LEDs) and backlight displays. A universal synthetic strategy is proposed for encapsulation and in situ passivation of perovskite nanocrystals in AlPO‐5 zeolite. The perovskite–zeolite composite exhibits enhanced photoluminescence emission and ultrahigh stability under ambient exposure or in water.