Enhanced stability of CsPbBr3 nanocrystals through Al2O3 and polymer coating

Abstract

Lead halide perovskite nanocrystals have emerged as a promising candidate for next-generation display applications due to their attractive optical properties and low-cost production. However, the environmental stability of perovskite remains a major challenge, hindering their practical applications and scalability for commercialization. In this study, we present an effective method to enhance the stability of CsPbBr₃ nanocrystals by coating them with a combination of Al₂O₃ and a polymer. The unique double protection structure significantly improves their resistance to moisture, heat, and polar solvents. It is worth noting that compared with the ordinary CsPbBr₃ nanocrystals, the modified nanocrystals have better stability and higher luminous intensity. After soaking in water for 360 hours, the modified nanocrystals retained 85% of their initial luminous intensity. Under optimal conditions, the luminous intensity of modified nanocrystals increased by 36%. Furthermore, the thermal stability and organic solvent resistance of the nanocrystals are improved compared with the nanocrystals uncoated with Al₂O₃. The synthesized white light emitting diode using the modified PNCs achieves a color gamut coverage rate of 129% under standard NTSC, and 95% under standard Rec.2020, indicating its potential for future display applications. This research presents a promising approach for the development of stable perovskite nanocrystals with enhanced performance in various optoelectronic devices.