Water-resistant and flexible all-inorganic perovskite nanocrystals films for white light-emitting applications

All-inorganic perovskite materials have many advantages such as adjustable emission range, narrow emission peaks, and good crystallinity, which have attracted widespread interest. They can be used as solar cells, LEDs, photodetectors, displays, and other optoelectronic devices. However, poor environmental stability is the major factor limiting its applications. We introduced a Poly(styrene-ethylene-butylene-styrene) SEBS polymer to create perovskite/SEBS composite films which have excellent stability even in the water environment. Besides, due to the elastic nature of SEBS, the composite films exhibited good mechanical deformability and could maintain most of its fluorescence intensity after being stretched hundreds of times. A WLED device was constructed by stacking CsPbBr 3 /SEBS films and CsPbI 3 /SEBS films over a blue LED. The WLED performed well with color rendering index of 82.6 with chromaticity coordination (0.35, 0.36) and color temperature 4784 K. Graphic Abstract In order to create a stable and flexible photoluminescent material, we combined a poly(styrene-ethylene-butylene-styrene) (SEBS) polymer and cesium lead-halide nanocrystals forming a flexible photoluminescent composite. The composite films show both good environment stability and excellent flexibility.