Cs4PbBr6@PDMS film prepared by a facile two-step method for wide color gamut backlit display

All-inorganic perovskites have been considered next-generation color converters in the backlit due to their shining optical properties. However, structural instability severely limits their pragmatic applications. Here, CsPbBr3/Cs4PbBr6 microcrystals (MCs) were successfully embedded in polydimethylsiloxane (PDMS) films by a facile two-step method. As-prepared PDMS films containing CsPbBr3/Cs4PbBr6 MCs (CsPbBr3/Cs4PbBr6 @PDMS) obtain high brightness and excellent stability. Meaningfully, the PDMS films not only serve as a double protective matrix that can be used to improve the stability of CsPbBr3/Cs4PbBr6 MCs, but also a flexible substrate with high transparency that allows the CsPbBr3/Cs4PbBr6@PDMS films to be used as color conversion materials for backlit displays. To our surprise, when PDMS is coated with CsPbBr3/Cs4PbBr6 MCs, the water, thermal and photostability are greatly improved, while the photoluminescence intensity only lost by 10%. Furthermore, by mixing CsPbBr3/Cs4PbBr6 MCs with K2SiF6:Mn4+ phosphors in PDMS, a monolithic film with high performance was obtained. Its color gamut can reach 127% of the NTSC 1953 standard and 95% of the REC. 2020 standard, exhibiting the bright prospects in the backlit display field.