Optical Properties And Application On WLED Of Lead Halide Perovskite Quantum Dots Synthesized By Grind Method

In recent years,as a new photoelectric material,lead halide perovskite quantum dots(QDs)have been widely studied.Due to their excellent optoelectronic properties,lead halide perovskite is also involved in a wide range of application fields,there are numerous research results in light emitting diodes(LEDs),lasers,X-ray imaging,scintillators and photodetectors.Among them,lead halide perovskite LEDs have attracted special attention of researchers all over the world due to the rapid increasment of electroluminescence efficiency.In this case,research on how to synthesize excellent lead halide QDs more conveniently and efficiently is also crucial.In this paper,a new method is proposed to synthesize lead halide QDs more efficiently and conveniently,and to achieve Mn2+ doping.Furthermore,the synthesis mechanism of the grinding method was discussed,and further research on the microstructure,optical properties and application of white LEDs was made.Specific work as follows:In second chapter,a new method for preparing lead halide perovskite quantum dots at room temperature is introduced.The preparation of ABX3 perovskite quantum dots is achieved by simple grinding.This strategy alleviates common harsh synthetic conditions such as precursor dissolution,atmospheric protection and high reaction temperature.According to experimental phenomena,we propose that the formation of perovskite structure is spontaneously formed by mixing PbX and AX.The grinding process is to help form more perovskite structures and turn large particles to nanoscale.Surprisingly,the perovskite nanocrystals synthesized in this way are capable of emitting light in the full wavelength range from visible light to near infrared,with a maximum photoluminescence quantum yield of 92%and excellent stability,and the feasibility of using this method to prepare perovskite quantum dots on white LED is verified by confirmatory experiments.In third chapter,the method of grinding and synthesizing perovskite quantum dots is further extended to synthesize Mn2+ doped CsPbCl3 and CsPb(Br/Cl)3 perovskite quantum dots with bimodal emission excitons,the problem of dissolving and heating the precursor in Mn2+ doping was alleviated.Grinding method synthesized Mn2+ doped CsPbCl3,CsPb(Br/Cl)3 perovskite nanocrystals at room temperature by Mn2+ provided by MnCl2,according to the phenomenon in our experiment,it is proposed that the process of grinding and synthesizing Mn2 +doped perovskite quantum dots at room temperature is actually the process of Mn-Pb ion exchange.It is worth noting that the quantum yield of perovskite-doped quantum dots with Mn2+ ions is significantly improved,which is more than 6 times higher than the original.