Controlled Synthesis And Luminescence Properties Of Bismuth Doping Material

Bismuth–doped luminescent material has showed remarkable application potential in lighting,optical fiber communication,biomedicine,and laser device,because of its adjustable luminescent spectra from ultraviolet to infrared（300–3000 nm）,covering biology window and optical fiber communication window,high quantum efficiency and many other advantages.In this paper,based on the current research of bismuth–doped near–infrared luminescent material,we carried out the research work on the controllable synthesis,luminescence properties and luminescence mechanism of Bi–doped[SiW₁₂O₄₀]^4–and CsPbI₃,those two kinds of NIR luminescent materials.Among them,in the structural analysis and the mechanism of those luminous material,we tried SXRD and EXAFs,to determine the elements form and the ligand environment of Bi.On the basis of the experiment,we have made a reasonable explanation on the luminescence mechanism.And the main research results and conclusions are as follows:1.Through ion exchange strategy,we obtained Bi–doped"Keggin"type polyoxometalate–cesium silicotungstic acid(Cs_3.0H_0.3[SiW₁₂O₄₀]_0.83·3.0H₂O)with anionic vacancy,instead of traditional methods.Then high temperature annealing with N₂ gas formed a Bi relevant NIR active center（BRACs）;The morphology and element distribution of the sample were characterized by SEM and EDS–mapping.Using the magic Angle spinning nuclear magnetic resonance（NASNMR）,high resolution synchrotron radiation X–ray diffraction（SXRD）,X–ray absorption fine structure（XANEs）,to make sure the structure of the samples and the existence of Bi element form and determine the ligand environment;At the same time,fluorescence spectrum analysis and fluorescence life analysis（Decay）were used to characterize and determine the optical properties and luminescence mechanism of the samples.2.The Bi doped near infrared active CsPbI₃ perovskite nanocrystalline materials were synthesized through hot injection method.Then using transmission electron microscopy（TEM）and X–ray diffraction spectrum（XRD）analysis for further characterization,to determine the morphology and structure of the samples.Through ultraviolet visible absorption spectrum analysis（Abs）,fluorescence spectrum analysis,near–infrared fluorescence lifetime analysis（NIR–decay）and near–infrared（NIR–PLQY）quantum efficiency analysis were used to characterize the optical properties of Bi doped CsPbI₃ quantum dots;Then the effective energy transfer process in CsPbI₃ quantum dot doped system was studied from semiconductor CsPbI₃ to Bi relevant NIR active center.Finally,through those analyses of structure and optical phenomena,the near infrared emission mechanism of the sample is further studied.