Two-Step Hybrid Passivation Strategy for Ultrastable Photoluminescence Perovskite Nanocrystals

Perovskite nanocrystals (NCs) are promising light-emitting materials for next-generation illuminations and displays. The main challenge for practical applications is to achieve high durability. Herein, a hybrid passivation strategy was developed to simultaneously enhance the photoluminescence quantum yield (PLQY) and the stability of perovskite CsPbBr3 NCs by two-step modification with surface halogen replenishment and atomic layer deposition. The hybrid passivation mechanisms regarding the repairing of NCs’ surface Pb–Br octahedron as well as insertion of inorganic AlO x on the NCs’ surface were unraveled. The obtained CsPbBr3 NC films not only have high PLQY but also retain 100% of original PL value after UV illumination for 48 h, which was quantitatively assessed as the most stable solid-state CsPbBr3 NC film ever reported. Based on the passivation method, a high-lumen white light-emitting diode (LED) device exhibiting working durability was successfully fabricated. This strategy is beneficial for fabricating ultrastable perovskite phosphors and significantly improving their potential in LED illumination and backlight displays.