Fabrication And Characterization Of QLED

After decades of development,quantum dot electroluminescent devices(QLED)have gradually moved from research to commercial applications.Due to the advantages of high color gamut,high brightness and narrow half–width peak,quantum dot materials(QDs)have attracted great attention in the display field.QDs are widely used in mobile phones,televisions,computers and other fields.QLED is a sandwich structure composed of electron transport layer,emitting layer and hole transport layer.Because of multilayer structure,QLED's manufacture involves a variety of materials and processes.The main purpose of this research is to obtain QLED with better electro–optical conversion efficiency(EQE)and longer life.Aiming at the existing problems of QLED,the research work of this paper is as follows: Synthesis of CdSe/ZnS core–shell quantum dots with high–performance of which PLQY over 80%,and use dodecyl thiol as ligand to exchange oleic acid molecules on the surface of quantum dots for high quality emitting layer material.Zinc oxide quantum dots and low–temperature annealing doped nickel copper oxide nanocrystals were synthesized by adjusting the material structure and composition as electron transport layer and hole transport layer materials with good performance.Each functional layer of the device is studied.Visible light absorption spectrum,TEM,AFM and other characterization techniques were used to characterize the materials and devices.Spectrometer,optical power meter and Keithley 2400 source meter were combined with MATLAB to realize the photoelectric performance test and data processing of the device and the photoluminescent fluorescence efficiency of quantum dot materials in different emission and absorption wavebands.It was found that the stability of the device could be improved by using nickel oxide as the hole transport layer,and the highest electron injection efficiency could be obtained by using 5% magnesium oxide.The optimal quantum dot layer thickness was obtained by using 3500 rpm spin coating,and its EQE was as high as 7.412%.