Synergistic enhancement of CsPbBr3 perovskite nanocrystals via ZnO and EPDM for stable wide-color-gamut display

All-inorganic perovskite CsPbBr 3 nanocrystals (NCs) are promising for wide-color-gamut displays due to their high photoluminescence quantum yield (PLQY) and narrow emission bandwidth, yet their ionic nature renders them susceptible to degradation by moisture, heat, and mechanical stress, while surface defects induce non-radiative recombination. Herein, we propose a synergistic protection strategy combining ZnO inorganic modification with EPDM flexible polymer encapsulation. A ZnO heterojunction is constructed in situ on CsPbBr 3 NCs via a solution method, after which the modified NCs are dispersed in an EPDM matrix to fabricate flexible composite films. Structural and optical characterizations confirm that ZnO modification effectively suppresses non-radiative recombination, prolonging the average photoluminescence (PL) lifetime to 14.54 ns. XPS and DFT calculations reveal strong interfacial chemical interactions between CsPbBr 3 and ZnO, with an adsorption energy of −1.923 eV, suggesting effective surface-defect passivation. Stability tests demonstrate that after 6 days of water immersion, heating at 90 °C for 60 min, 200% mechanical stretching, and 100 h of UV irradiation, the composite retains 65%, 60%, and 80% of its initial PL intensity, respectively, showing substantially improved multidimensional stability. A white light-emitting diode fabricated using the film exhibits CIE chromaticity coordinates of (0.34, 0.32) and color gamut coverages of 121.2% NTSC and 98.2% Rec. 2020. This strategy simultaneously addresses defect passivation and environmental instability in perovskites, offering a feasible route towards commercial perovskite-based optoelectronic devices.