Study On Metal Halide Perovskite Light Emitting Device Based On Inoragnic Transport Layer

Metal halide perovskite are excellent optoelectronic semiconductor materials for solar cells,light emitting diodes,photodetectors and lasers due to their long carrier diffusion length,high defect tolerance,adjustable band gap,and solution processing.On account of high luminous color purity and adjustable luminous wavelength,metal halide perovskite light-emitting diodes are expected to emerge in low-cost high-definition display applications.At present,the light-emitting diodes based on metal halide perovskites have the bottleneck of poor stability.This study aims to find stable and reliable inorganic transport material for adjusting the band structure and preparing reliable and excellent perovskite light-emitting diode.The research work of this thesis mainly includes:1.Adding PEO and PVP to the precursor solution to improve the crystallinity and compactness of the perovskite film,and increase the solubility of CsPbBr3 and passivate the grain boundaries by adding MABr.Studies have shown that the addition of PEO and PVP can reduce the leakage current of light emitting diodes,and the addition of MABr can increase the fluorescence intensity of CsPbBr3 films.Based on these resuts,a transport layer free metal lead halide perovskite light-emitting diode with high brightness and high stability was prepared.2.?-? nitrides is an band gap adjstable inorganic semiconductor material system,and studied as possible transport layers for halide perovskite light-emitting diode in this thesis.Nitride films were deposited on the surface of metal halide perovskite by atomic layer deposition technology to prepare nitride-metal lead halide perovskite heterogeneous junctions.X-ray photoelectron spectroscopy was used to characterize the interfacial band alignment of the heterojunction.The intensity of the photoluminescence was used to evaluate the carrier confinement effect of different heterojunctions.the band arrangement of perovskite/nitride heterojunction are determined to be type I,thus the nitrides have a significant confinement effect on the carriers in the lead halide perovskite,and can significantly enhancing the photoluminescence intensity.3.Increasing the optical band gap of NiO and ZnO through Mg doping,and thereby adjusting the band position of the carrier transport layer,was found helps to improve the electro-optical conversion efficiency of the perovskite light-emitting diode.Using hydrofluoroether as a dispersant for Mg:ZnO nanocrystals,the research proves that it can be applied to the preparation of CsPbBr3 polycrystalline films and CsPbBr3 quantum dot devices.The hole transport layer,the perovskite light-emitting layer,and the electron transport layer are all made of inorganic materials and are all prepared by solution method.