Synergistic mesoporous silica confinement and PMMA encapsulation enabling highly stable CsPbX3 composite films for wide-color-gamut backlighting

Abstract

Metal halide perovskite quantum dots (PQDs) have attracted considerable attention for wide-color-gamut display applications due to their high quantum yield and narrow-band emission characteristics. However, their poor stability has long been a major obstacle to practical applications. In this study, PQDs were confined within SBA-15 molecular sieves via a hot-injection method. The resulting composites were further embedded into a poly(methyl methacrylate) (PMMA) matrix, successfully yielding tricolor composite films. These composite films retain vivid emission colors and exhibit excellent optical performance. Compared with the corresponding B, G, and R-SBA powders, the PMMA-composited blue, green, and red films show almost no noticeable red shift in their maximum emission wavelengths. Meanwhile, the full width at half maximum (FWHM) of the emission peaks is significantly narrowed, indicating improved spectral purity. In addition, the composite films demonstrate outstanding water stability. After immersion in water for 840 h, the photoluminescence (PL) intensities of the B, G, and R-SBA/PMMA composite films remain at approximately 75%, 110%, and 46% of their initial values, respectively. Furthermore, white-light LEDs constructed from the tricolor composite films exhibit a wide-color-gamut, which covers 131% of the NTSC standard. These results indicate that the composite films show great potential for display applications. Overall, this work demonstrates that the composite films, combining excellent optical performance with superior water resistance, provide a promising strategy for applications in LED backlighting and display devices.