Metal halide perovskite nanocrystal with fluorescence enhancement in wet and acidic environment

Metal halide perovskite nanocrystals have excellent prospects in solid-state lighting, flexible display, sensing, and other optoelectronic applications due to their superb photoelectric properties (high quantum efficiency and fast carrier diffusion speed). However, they are susceptible to environmental factors such as ultraviolet radiation and polar solvents. Especially in a water environment, poor stability seriously restricts the application of perovskite optical devices . In this paper, a kind of porous polymer (ethylene-vinyl acetate copolymer , EVA) and perovskite nanocrystals were mixed to form perovskite nanocrystals-EVA composites. The obtained composites were aged in water for 21 days, and the fluorescence enhancement was 170 times. Even in a strongly acidic environment, the fluorescence enhancement was 91 times. The information encryption mode of the composite material can effectively encrypt information in a wet environment due to the change of light wavelength, making a white light-emitting diode (w-LED). This metal halide perovskite nanocrystals-EVA composite will unleash a wide variety of solid-state lighting and flexible display possibilities that are limited by the use of existing methods in humid and strongly acidic environments.