白色磷光OLEDs的制备及性能研究

Preparation and properties of white phosphorescent OLEDs

采用蓝色、黄色磷光混色的发光方式实现白光有机电致发光器件(OLEDS),其中黄色发光层由红色和绿色磷光材料混合而成,器件的结构为ITO/MoO3(30nm)/NPB(40nm)/mCP:FIrpic(8%)(50nm)/CBP:R-4B(1%):GIrl(14%)(xnm)/BCP(10nm)/AlQ(40nm)/LiF(1nm)/Al(100nm)(x=2,3,4,5,6nm)。对器件的效率、亮度等对比发现,当x=5nm时,器件的性能最佳,最大亮度为9 471cd/cm2,效率为23.5cd/A,色坐标(0.32,0.35)。实验表明,影响器件色稳定性和效率低的原因是电子和空穴迁移随驱动电压变化响应不一致引发激子复合区域的移动。

In this paper, white phosphorescent organie light-emitting devices （OLEDs） were prepared with blue phosphorescent layer and yellow phosphorescent layer, and the yellow light-emitting layer is com- posed of red and green phosphorescent materials. The device structure is as follows： ITO/MoO3 （30 nm）/NPB（40 nm）/mCP.Flrpic（8%） （50 nm）/CBP： R-4B（1%） ： Girl（14%） （5 nm）/BCP（10 nm）/ A1Q（40 nm）/LiF（lnm） /AI（100 nm） （x=2,3,4,5,6 nm）. By comparing the efficiency and brightness of the device, itr s indicated that the device has the best performance when x = 5 nm. The maximum brightness is 9 471 cd / cm2 , the maximum current efficiency is 23.5 cd / A , and color coordinates are （0.32,0. 35）. From the experiment,the reason for affecting stable color and low efficiency is the move- ment of exciton recombination zone because of the different responses to the drive voltage for electron and hole mobilities.