Direct Hot-Injection Synthesis of Lead Halide Perovskite Nanocubes in Acrylic Monomers for Ultrastable and Bright Nanocrystal–Polymer Composite Films

摘要： In recent years, lead halide perovskite nanocrystals (NCs) have attracted significant attention in both fundamental research and commercial applications due to their excellent optical and optoelectrical properties. However, the protective ligands on the surface of the perovskites NCs could be easily removed after the tedious process of centrifugation, separation, and dispersion, which greatly hampers their stability against light, heat, moisture, and oxygen and limits their practical applications. Here we report a new post-processing-free strategy (i.e., without centrifugation, separation, and dispersion process) of using an UV-polymerizable acrylic monomer of lauryl methacrylate (LMA) as the solvent to synthesize CsPbBr3 NCs, and then adding polyester polyurethane acrylates oligomer, monomer (IBOA) and initiator for directly UV polymerization to fabricate NC-polymer composite films. These films exhibited an improved photoluminescence quantum yield (85-90%) than classic NC-film (40-50%), which were processed using octadecene (ODE) as the solvent for NC synthesis and post-processed for UV polymerization. Significantly, the as-fabricated films by post-processing-free strategy exhibited excellent photostability against strong Xe lamp illumination; while the other films using classic methods were quickly photo-degraded. Meanwhile, these NC-polymer composite films showed good stability against moisture and heating when aging in water at 50oC for over 200 hours. These films, along with K2SiF6:Mn4+ (KSF) phosphor emitters, were used as downconverters for blue LEDs in liquid crystal displays with a wide color gamut of 115% in the International Commission on Illumination (CIE) 1931 color space. This work provides a facile and effective strategy for the preparation of ultrastable and bright color-conversion NC films for the development of the next-generation wide color gamut displays.