Homogenous luminescent perovskite-acrylate based films with self-wrinkling patterned surface for flexible full-color backlight display

All-inorganic lead halide perovskite nanocrystals (PNCs) are regarded as promising materials for flexible full-color backlight displays owing to their exceptional optoelectronic properties. However, their practical utility is impeded by undesirable luminescence characteristics, as well as poor mechanical properties and stability. Herein, CsPbBr₃ PNC-based flexible films with uniform luminescence are fabricated by regulating the particle size of PNCs and their uniform dispersion in films, and by creating self-wrinkling micro/nano-structured surfaces, which feature ultrahigh stability, hydrophobicity and stretchability. CsPbBr₃ PNCs are obtained by employing styrene as the solvent, which yields enhanced particle size distribution and photoluminescence purity (∼7.5 nm in size; 85 % quantum yield). The styrene/CsPbBr₃ solution can photopolymerize with butyl acrylate, methyl methacrylate, and vinyl-polyhedral oligomeric silsesquioxane (POSS) to realize CsPbBr₃-containing composite films (Poly@PNCs) with well-dispersed PNCs. The optimized Poly@PNCs films exhibit self-wrinkling micro/nano-structured surface patterns, while the degree of self-wrinkling shows a strong positive correlation with POSS concentration. These properties of Poly@PNCs films facilitate the fabrication of flexible light-emitting displays with an area of 25 cm², exhibiting wide color gamut, high luminous efficiency, and excellent color-rendering index. The demonstrated method paves the way for the fabrication of stable, homogenous perovskite-based luminescent materials for flexible optoelectronic devices.