Stability Enhancement of CsPbBrI2 Glass Powder in PS Film via a Heat-Water Cyclic Treatment for Backlight Display

Nowadays, an all-inorganic metal halide perovskite (CsPbX3, X = Cl, Br, and I) has shown excellent prospects in liquid crystal display (LCD) backlight device applications. However, in order to better meet the market’s development, the stability of CsPbX3 still remains an urgent problem to be solved. Herein, a heat-water cyclic process of CsPbBrI2 glass powder (RGP) designed to improve stability is proposed. Excitingly, the treated RGP shows better optical properties and heat resistance. Moreover, RGP@PS was prepared with high blue light, water, and heat stabilities. It is particularly noteworthy that RGP6@PS was continuously exposed for 268 h at 60 °C and 90% relative humidity in the blue light (447 nm, 880 W/m2) environment with no decrease in brightness. It illustrates that the CsPbX3 films have made an important breakthrough in stabilities. The LCD device based on RGP@CsPbBr3@PS was designed with a wider color gamut (126%) compared with NTSC 1953. This study explores a new strategy to improve the stability of CsPbX3 thin films for LCD light conversion films.