Study On The Synthesis,luminescence Control And Application Of Cs_nPbX_n+2?n=1,4,X=Cl,Br,I?Inorganic Perovskite Nanomaterials

Recently,perovskite materials,due to their excellent optical and electrical properties,have attracted the attention and favor of researchers and have potential application value in biological imaging,backlight display,solar cells,laser,photoelectric detectors etc.fields.Because of high carrier mobility,long lifetime carrier transport characteristics,and has a strong optical absorption capacity,perovskite has an outstanding progress in solar cells.Moreover,perovskite with direct band gap semiconductor,has been developed in the field of optics.Perovskite nanomaterials have attracted much attention because of their excellent optical properties.In this paper,the microstructure and optical properties of CsnPbXn+2(n=0,4,X=C1,Br,I)perovskite nanomaterials obtained by different preparation methods have been studied,and the possibility of using them as the next generation optical device materials has been analyzed.The main research results are as follows:In the first chapter,the research background,the preparation methods,the research status and application prospect of perovskite materials in solar cells,light-emitting diodes and laser fields are introduced briefly.The basic knowledge and luminescence principle of perovskite nanomaterials are ordinary introduced.In chapter two,the structure,optical properties and applications of Csi-mFAmPbX3 quantum dots are studied.The effect of cationic doping in A position on the optical properties and stability of perovskite quantum dots was investigated.Finally,white LED devices with simple structure are fabricated and their applications in lighting and display fields are analyzed.In chapter three,the controllable preparation of pure Cs4PbBr6 and pure CsPbBr3 nanomaterials is realized by simply changing the content of ligand in the precursor prepared by ligand-assisted precipitation method.By studying the optical properties of single nanoparticles of Cs4PbBr6,it is confirmed that the emission of Cs4PbBr6 nanoparticles is derived from the photoluminescence centers formed by the trapped excitons in the defect states of halogens.In chapter four,we developed a new synthesis method to prepare ultrathin CsPbBr3 perovskite nanoplatelets.In the course of studying the optical structure and optical properties of CsPbBr3 ultrathin perovskite nanoplatelets,we found that the thin thickness endows quantum confinement effect to the ultrathin perovskite nanocrystals,which makes the optical properties of ultrathin CsPbBr3 perovskite nanoplatelets obviously different from those of the nanocrystals of the same composition.The results show that the band gap increases,the luminescence show the blue shifts,and the quantum yield is much higher than that of the CsPb(BrCl)3 nanocrystals with the same emission.Finally,the main contents of this paper are summarized and prospected.