Research On High Efficiency Phosphorescent Organic Electroluminescent Device Based On Single Light-emitting Layer

Organic light-emitting devices(OLEDs)have attracted a lot of attention due to their inherent characteristics.OLEDs play an important role in display(LCD),solid-state lighting,communication terminals,military fields,aerospace and other fields.After nearly 30 years of continuous development,OLEDs have gradually entered the industrialization stage,and its market share in display equipment and lighting equipment has gradually expanded.In recent years,a variety of phosphorescent materials have made important breakthroughs,laying a solid foundation for the rapid development of OLED.The main work of this paper is to optimize the single-layer yellow and blue devices.The specific work is as follows:We first fabricated a set of four devices with the Fir6 as emitting layer.By changing the doping ratio of TCTA and Tmpypb,the turn-on voltage of device is3.33v.Besides the spectrum is very stable and the maximum efficiency is 1.45 cd/A(1.06 lm/W).Next,we replace TPBi with Tmpypb and the second group of experiments were carried out base of the original structure.Devices O1-O4 achieve the maximum brightness at 8 V.The maximum efficiency is 9.59 cd/A(7.38 lm/W),respectively.The device efficiency and brightness are significantly improved compared with devices A-D.Next,we explore the yellow light device of single light-emitting layer.The maximum brightness of the device E-H is 43640 cd/m~2.The maximum efficiencies is32.6cd/A(24.8 lm/W).As we can see,the reduced density of hole transport materials in doping structure can optimize the balance of carriers transport and improve the performance of devices,which has great improvement on devices performance.We have studied the photoelectric properties of monochromatic yellow and blue phosphorescent materials through two groups of experiments.The performance of the device has been greatly improved by optimizing the structure of the mixed-host materials and the transport layer.The performance of the devices have been greatly improved.