Improving photoluminescent water-stability of CsPbBr3 perovskite nanocrystals via constructing nanocrystals/polymer composites with hydrophobic surfaces for LED applications

With quick development of optoelectronic devices, lead halide perovskite nanocrystals (PNCs) have been extensively researched due to their excellent optoelectronic and luminescent properties. However, the water-induced low stability seriously restricts their applications. In this study, CsPbBr3 PNCs/polymer composite films are prepared based on even dispersion of PNCs and ultraviolet (UV)-induced chemical crosslinking of methyl methacrylate (MMA) monomers and vinyl silicone oil (VT-PDMS) oligomers. The optimized polymer/PNCs composite film exhibits high photoluminescence quantum yield (PLQY) of 82% comparable to common PNCs, as well as high surface hydrophobicity. This film shows high photoluminescence (PL) intensity (90% of original value) after air aging for 60 days. Its high surface hydrophobicity is attributed to use of VT-PDMS oligomers bearing Si element with low surface energy. Light-emitting-diode (LED) device is constructed employing this optimized composite film, and its color coordinates (0.343, 0.334) is rather close to that of standard white light. Specifically, high PL and surface hydrophobic properties of specimens are simultaneously achieved. The importance of this work can lie in a mild rapid preparation of hydrophobic CsPbBr3 PNCs/polymer nanocomposites with stable white-light emission for commercial LED devices.