Preparation And Control Crystallization Of CsPbBr₃ Nanocrystalline Glass

CsPbX₃（X=Cl,Br,I）perovskite quantum dots（QDs）are nanocrystals（NCs）with a size of 1-10nm.Due to their excellent photoelectric properties,such as tunable emission wavelength,narrow emission bandwidth and high quantum efficiency,they have potential applications in backlight display,LED lighting,photodetectors and other fields.However,CsPbX₃ QDs have poor stability in the atmospheric environment and are easy to deteriorate and decompose.The transparent inorganic glass with a dense network structure can protect them well and improve their stability.This paper mainly studies how to control the precipitation of CsPbBr₃ NCs in the glass matrix.The effects of variables such as doping light,thermistor,changing the temperature and time of heat treatment and changing the exposure time under ultraviolet lamp on the crystallization of CsPbBr₃ NCs glass are studied and analyzed.The regulation of these factors is proved.The controlled crystallization of CsPbBr₃ NCs glass is of great significance in many application fields.The main research work of this paper is as follows:1.Firstly,the low melting point fluorophosphate glass was selected as the matrix material,which can reduce the volatilization of bromine at high temperature.Through the traditional melting quenching method,CsPbBr₃ NCs did not precipitate in situ in the glass after melting at 850℃ for 20min,and the subsequent heat treatment successfully precipitated CsPbBr₃NCs in the glass.It is found that the temperature and time of heat treatment have a great influence on the precipitation of CsPbBr₃NCs in fluorophosphate glass.The experimental results show that the heat treatment at 350℃ for 2h is relatively suitable.Under the heat treatment conditions of 350℃ and 2h,it was proved that the addition of light and heat sensitive agents,the change of exposure time after addition and the concentration of light and heat sensitive agents had a certain regulatory effect on the precipitation of CsPbBr₃ NCs in fluorophosphate glass.2.The widely studied phosphorus silicate glass is selected as the matrix material,and the phosphorus silicate glass has good compatibility with the doped ions.By melt quenching method,CsPbBr₃ NCs are not precipitated in situ in the glass by melting at 950℃ for 20 min,and the subsequent heat treatment makes CsPbBr₃ NCs successfully precipitated in the phosphorus silicate glass with light and heat sensitive agents.It is found that the change of heat treatment temperature and time also has a great influence on the crystallization of CsPbBr₃ NCs phosphosilicate glass,and420℃,6h heat treatment is relatively suitable.Under the heat treatment condition of 420℃ and 6h,it was proved that the change of exposure time and the change of composition of light and heat sensitive agent had a regulatory effect on the precipitation of CsPbBr₃NCs in phosphate silicate glass with light and heat sensitive agent.