Synthesis Of Doping & Heterogeneous Perovskite Nanocrystals And Research On Optical Applications

CsPbX₃(X=Cl,Br,I)perovskite nanocrystals have become a research hotspot and been widely applied in the field of lasers and photovoltaic devices in recent years due to their excellent photoelectric properties.Ion doping and surface coating,as common methods to improve the stability of perovskites,have also been studied in depth.This article focuses on the application of Mn²⁺doped perovskite in active waveguide fibers,the preparation of CsPbBr₃@ZnS heterojunction and the study of carrier dynamics.The main research results are as follows:(1)CsPbBr₃ quantum dots have been selected as light-emitting source to mix with polymers to prepare waveguide fibers.The optical transmission loss coefficient is determined to be 2.6 cm^-1,which is an order of magnitude lower than that of traditional quantum dot doped waveguide fibers.(2)The Mn²⁺doped perovskite quantum dots were synthesized by hot injection method,which realizes the separation of absorption and photoluminescence spectra.The influence of reabsorption has been totally eliminated in the Mn²⁺doped perovskite quantum dots.The optical transmission loss coefficient of the waveguide fiber prepared by using Mn:CsPb(Cl/Br)₃quantum dots as the light-emitting source is only 0.33cm^-1,which is two orders of magnitude lower than that of the traditional quantum dot-doped waveguide fiber.(3)ZnS shell has been grown on the surface of CsPbBr₃ nanocrystals,forming CsPbBr₃@ZnS heterojunction with a Type-II band structure.Its lifetime was about 15 times longer than that of CsPbBr₃ nanocrystals.(4)The carrier dynamics in the CsPbBr₃@ZnS heterojunction has been researched,revealing the process of carrier transfer between core and shell.The spontaneously amplified radiation threshold of CsPbBr₃@ZnS heterojunction as optical gain has determined to be35?J·cm^-2,which is unfavorable for its application in laser.