Design,Preparation And Properties Of Rare Earth-Doped CsPbBr₃ Nanocrystals Embedded In Fluorophosphate Glass-Ceramics

Cesium lead halide perovskite quantum dots（CsPbX₃（X=Cl,Br,I）QDs）have attracted great research interest in solid lighting,liquid crystal display and solar cells due to their unique photoelectric properties,such as tunable photoluminescence peak（400-800 nm）,narrow emission linewidth and high quantum efficiency through halide composition engineering and quantum confinement effect.However,due to its ionic properties and low synthesis energy,CsPbX₃ QDs face serious thermal and chemical stability problems in the natural environment.In addition,the toxicity of Pb²⁺ions have also greatly hindered its commercialization process.Firstly,this paper summarizes the definition,characteristics and luminescence principle of QDs,investigates and summarizes the research progress of CsPbX₃ QDs at home and abroad.Then aiming at the existing problems,the stability of CsPbX₃ QDs was improved when embeded fluorophosphate glass,and the effects of glass components on the B-site cation composition and optical properties of CsPbX₃ QDs were studied and analyzed.Finally,based on the specific application of CsPbX₃ QDs embedded glass in solid-state lighting,the effects of glass composition and heat treatment time on the color temperature and color coordinates of the emitting light source when it is used as a color converter are analyzed.1.Aiming at the problem of poor stability of CsPbX₃ QDs in natural environment,the in-situ growth of CsPbX₃ QDs in fluorophosphate glass matrix is controlled by melting quenching and heat treatment.The protection of dense glass network structure effectively improves the thermal,wet and oxygen stability of CsPbX₃ QDs.By adjusting the glass composition,the B-site cation doping of CsPbX₃ QDs in the matrix material is realized,and then the photoluminescence properties of CsPbX₃QDs are regulated.The existence of CsPbX₃,CsPbX₃:Y³⁺,CsPbX₃:Lu³⁺,CsPbX₃:La³⁺QDs in the matrix material was confirmed by X-ray diffraction,transmission spectrum,photoluminescence excitation spectrum and emission spectrum,and their optical properties were emphatically analyzed.In addition,through the observation and calculation of CsPbX₃ QDs photoluminescence low energy tail,photoluminescence half height width and Urbach energy value,the possible changes of defect density of states in nanocrystals caused by Y³⁺,Lu³⁺,La³⁺doping are analyzed.The FWHM of CsPbX₃ QDs embedded glass prepared in this paper is about 20 nm under 365 nm ultraviolet light and its photoluminescence quantum efficiency is up to 60.15%.2.In view of the lack of red component in the emission light source when CsPbX₃ QDs embedded glass is used in the color converter in solid-state lighting,Eu₂O₃is introduced into the glass precursor.The existence of Eu³⁺ions in the matrix material is confirmed by the analysis of the absorption spectrum and fluorescence spectrum of fluorescent substances in the glass precursor.By controlling the heat treatment time,the changes of color temperature and color coordinates of CsPbX₃QDs embedded glass containing Eu³⁺ions were studied and analyzed.After the introduction of Eu³⁺ions,CsPbBr₃QDs embedded glass showed multimodal emission under ultraviolet light after heat treatment at 360℃for 4 hours.Its color coordinate is（0.244,0.243）and the color temperature is6000 K.