Investigation Of Inorganic Cesium Lead Perovskite QDs And The QDs Light-Emitting Devices

Since the 21st century,light-emitting diodes(LEDs)have gradually occupied the main market for light sources and display devices.How to produce LEDs with lower prices and better luminous performance has also become an issue of concern.With the development of luminescent material research,all-inorganic Cs Pb X₃(X=Cl,Br,I)perovskite quantum dots have become a new type of perovskite.The material has the characteristics of high fluorescence quantum efficiency,adjustable emission wavelength,simple preparation and low cost.It is widely used in solar cells,light-emitting diodes,lasers,photodetectors and other fields.The CsPbX₃(X=Cl,Br,I)perovskite quantum dot light-emitting device has good monochromaticity,and the light-emitting wavelength range can be adjusted by the halogen ratio,the energy conversion rate is high,the working temperature is relatively low,and the work is longer.Longevity has received extensive attention from R&D personnel.The fluorescence quantum efficiency of perovskite quantum dots is an important factor affecting the luminous efficiency of the device.In this paper,the synthesis conditions of Cs Pb Br₃ perovskite quantum dots and Cs Pb I₃ perovskite quantum dots are studied and optimized,and the reaction conditions are explored for the crystallization of perovskite materials.Characteristic and luminescence characteristics,the reaction time of Cs Pb Br₃ perovskite quantum dots is optimized to 5s,the reaction temperature is 180?,the reaction time of Cs Pb I₃ perovskite quantum dots is 10 s,and the reaction temperature is 180?,and the crystal is obtained.Quantum dots with high quality and uniform size,the number of defect states in the quantum dot lattice is small,the probability of radiation recombination is high,and the quantum dots have good luminescence properties;the properties of quantum dot films prepared under different preparation conditions are studied,and the film rotation is optimized.The coating rate is 3000 rpm,the spin coating is 1 min,the annealing time is 10 min,and the temperature is 80°C to obtain perovskite quantum dots with fewer defects,uniform film,and more excitons per unit area,which means higher luminous efficiency.Thin film,at the same time in-depth analysis of perovskite quantum dot film photoluminescence spectrum,photoluminescence excitation spectrum,in order to apply perovskite quantum dot materials to light-emitting devices.This paper studies whether the surface morphology of Ti O₂ and Sn O₂ in the ITO conductive glass substrate of different electron transport layer materials have good carrier transport characteristics.Based on the materials in the ITO substrate and the transmission spectrum and spectrum of the basic FTO,it is found that Sn O₂ It exhibits a good surface morphology and can produce lower surface roughness and good crystallinity when in contact with perovskite,reduces the surface recombination state,and reduces the possibility of radiation recombination.On this basis,a double perovskite quantum dot LED device with ITO/Sn O₂/Cs Pb Br₃/Cs Pb I₃/PVK/Au electrode structure is prepared.The maximum external quantum efficiency is 1.79%,and the maximum brightness is 63 cd/m².