Facile Preparation of CsPbBr3 Nanocrystals/Ethylene Vinyl Acetate Copolymer Composite Films with Long Term Stability and Flexibility for X‐ray Imaging.

CsPbBr3 perovskite nanocrystals (NCs)/ethylene vinyl acetate (EVA) composite flexible films were synthesized through a two‐step process. Firstly, CsPbBr3 nanocrystals with size of ~15 nm were synthesized via hot‐injection method, then the nanocrystals were dispersed in toluene as well as dissolution of EVA. The as‐prepared films emitting high purity of 90 % green color and photoluminescence quantum yield (PLQY) of 80 % with CsPbBr3 nanocrystals loading of 5 % wt under X‐ray. Owing to the EVA encapsulating of CsPbBr3, the composites show long‐term stable luminescent properties in atmosphere and even in water. Also, with the EVA as matrix, the composite films are ponent to be repeated bent for 1500 cycles without losing PL intensity property obviously. The X‐ray image with high contrast was captured at dose rate of ~25 μGyair/s(~0.09 Gy/h), that were estimated via calibrated apparatus. These results indicate that the CsPbBr3/EVA composite film has great potential application in fields of radiation detection and especially of X‐ray imaging. [ABSTRACT FROM AUTHOR]