Synthesis And Optical Properties Of Two Inorganic Luminescent Materials

All-inorganic perovskite CsPbX₃?X=Cl,Br,I?with excellent physicochemical properties has great application potential in the field of optoelectronic devices,and the devices are closely related to the study of material synthesis and basic properties.At present,the synthesis of small-sized CsPbX₃ and the controversy of the optical properties of the derived phase CsPb₂Br₅ are still hot topics in research.This paper discusses the preparation of ultra-fine CsPbBr₃ nanowires,the evolutionary relationship between CsPbBr₃ and CsPb₂Br₅,the optical properties of CsPb₂Br₅,First-principles theoretical calculations combined with experimental verification to study the luminescent properties of inorganic phosphors.The main contents are as follows:1)CsPbBr₃ has a very fast nucleation and crystallization rate due to the extremely strong ionic characteristics,leading to challenges in the synthesis of ultra-fine nanowires.In this paper,the template-limited growth strategy was used to prepare CsPbBr₃ ultrafine nanowires with a radial size of about 2 nm.The best preparation conditions of ultrafine nanowires were obtained by adjusting the morphology of the product by changing the stirring time,the perovskite ion concentration,PMMA,and post-treatment.2)Dual-phase CsPb₂Br₅-CsPbBr₃ is a promising way to improve device stability,but the evolutionary relationship between CsPbBr₃ and CsPb₂Br₅,and the optical properties of CsPb₂Br₅ are still controversial.In this thesis,room temperature saturated recrystallization method is used to prepare CsPbBr₃ and CsPb₂Br₅ nanosheets at high lead molarity.We found that CsPbBr₃ nanoplates were generated in the early stage of the reaction,and CsPb₂Br₅ nanoplates were formed in the late stage of the reaction with PbBr₂,and CsPb₂Br₅ had no visible fluorescence emission.3)The first-principles theoretical calculations can effectively supplement the experimental results and help to study the physical and chemical properties of new materials more thoroughly and comprehensively.In this paper,the high-temperature solid-phase method is used to prepare the inorganic phosphor BaSnSi₃O₉.The optical properties of the inorganic phosphor BaSnSi₃O₉ are studied by first-principle theoretical calculations combined with the experimental verification of Eu ion optical probes.