Study On The Synthesis Of Inorganic Lead Halide Cesium Perovskite And Its Device Properties

With the development and progress of modern society,The energy of people's demand is increasing year by year,but the storage of non-renewable fossil fuels is decreasing year by year such as oil and natural gas.The use of energy conservation has become an important problem.In the field of lighting,light-emitting diodes?LEDs?as an energy-saving,green products have been widely valued.At present,LED has shortcomings such as high cost of raw materials,complicated preparation process,complex optical design,and efficiency to be improved,so it has become a concern for researchers to find new luminous materials to improve the luminous efficiency of LED.Perovskite?ABO₃,of which A is big radius cation,B for small radius cation,O for anionic?is a direct band gap semiconductor material,it has the fast carrier mobility,big exciton binding energy and long diffusion distance?100 nm 3 microns?,low trap density(5 x 10¹⁶ cm^-3),narrow spectral absorption width?300 800 nm,the absorption rate of 5.7 x 10⁴?etc.,so it coude be the next generation of the LED's ideal material.Compared.With organic-inorganic hybrid perovskite material,pure inorganic perovskite material CsPbCl₃ has the advantages of high stability and cheap.However,its low luminous quantum efficiency and narrow luminous color gambit limit its further application.Aiming at this problem,this paper carries out the following three aspects of research:?1?In this paper by using chemical mechanical to produce solvent-free synthesis perovskite quantum dot material,adding different proportion of reactant to stainless steel tank,by setting the different ball milling time?0.5 h 1.5 h?,different ball mill speed?400 RPM to 580 RPM?to get the different sizes of nanoparticles and the different components of inorganic lead halide cesium perovskite materials,implements the perovskite nanoparticles luminous range in 410 nm to 688 nm covers all,in this way,the synthesis of perovskite not only uniform particle size distribution?13 nm or so?,but also the absorption peak emission peak sharp and symmetrical.Compared with heat injection and ion exchange,the method is simple and suitable for industrial production.?2?Different halogen?Cl,Br,I?doped perovskite nanocrystals were synthesized by changing the type and proportion of halogen ions.The visible light range of 412nm⁶32nm color adjustable.The purity of perovskite is high,the color gamut is larger than the international NTSC standard gamut,and the CsPbCl₃ luminescence gamut is broadened.?3?We through Mn doping to get the dual luminescence system of CsPbCl₃.Through changed the ratio of doping Mn to changed the luminescence color of the dual luminescence system is regulated.The luminescence position of Mn particle doping remains unchanged at around 580 nm.Moreover,the synthesized perovskite maintained the optimal phase performance,and the particles maintained the cubic morphology,with an average size of about 13 nm and a spacing of 0.39 nm between crystal surfaces.The addition of Mn ions greatly increases the stability of perovskite.In relative humidity is 40% of indoor environment can be held steady for 30 days or more,and the luminous intensity is not attenuation,by the way the fluorescence quantum efficiency of perovskite materials greatly increase,compared to not doped inorganic perovskite materials,the fluorescence quantum efficiency from 13.3%,up to 40.7%.With the basis of Ga N substrate,we coated perovskite nanocrystalline materials,to produce the white LED devices,with the increase of Mn doping ratio,LED devices present a purple,warm white,orange.When the proportion of Mn doping reaches 10%,the luminance of LED devices reaches 13.8 lm W^-1,which significantly improves.Compared with 2.6 lm W^-1 of undoped quantum dots.Through the research in this paper,the luminescence efficiency and color gamut of CsPbCl₃ nanocrystals are significantly improved,it's providing a new idea for the preparation of pure inorganic perovskite quantum dots and their luminescent devices.