The Study Of The Properties Of White Organic Light Emitting Didoe

WOLED has made remarkable achievement after years of development, but the performance of the device is still subject to the conditions of process and material. This thesis mainly studies on the design and optimization of device structure to get high efficiency and stable WOLED on the base of existing material. I mainly research the structure of the hybrid white light device and the role of the charge control layer.To begin with the research of the FP-WOLED. I used Rubrene ultra-thin layer as the yellow light emitting layer in order to get a simple structure and high efficiency of WOLED. The thickness of the ultra-thin is optimized. When the thickness of Rubrene is0.2 nm, the max brightness is 5893 cd/m2, and the max power efficiency is 1.814 lm/W.But the blue lightemitting is insufficient. Next, I used TAPC instead of CBP as the host and got the stable white device through to changing the thickness of the blue light emitting laye.When the thickness is 15 nm, the max brightness is 10061 cd/m2,and the max power efficiency is 10.56 lm/W, the CIEx,yis(0.334,0.390) at 8 V. Finaly, I used0.5 nm FIrpic as blue ultrathin layer and then inserted spacer layer TAPC to balance the excitons distribution. When the thickness of spacer layer is 3 nm,the max brightness is24771 cd/m2,and the max power efficiency is 12.03 lm/W, the CIEx,yis(0.334,0.390) at8 V. Compared with devices which using TAPC as the host of blue light emitting layer, the max brightness is increased by 146%, and the max power efficiency is increased by13.6%. I finaly got the white device which simple structure and stable white light.The following is the study of phosphorescent white light device, exploring the role of charge control layer on the carrier distribution and broadening the exciton compound area. At first I inserted charge control layer in the yellow light emitting laye and optimized the number of charge control layer. When the number is one, the max brightness is 39747 cd/m2, and the max power efficiency is 20.30 lm/W. By comparing the performance of the devices, conclusion that charge control layer can help to broaden the exciton distribution and balance the transmission of the carrier. Then I fsbricated the device using the CBP as the charge control layer and using the TPBi doped with FIrpic as blue lighting emitter layer.And the thickenss of blue lighting emitter layer is optimized to get the white device which the max brightness is 23290 cd/m2, and the max power efficiency is 9.27 lm/W, The maximum brightness and power efficiency is 39747cd/m2 and 20.30 lm/W. Next, on the basis of the one layer charge limited layer for yellow lightemitting devices, make blue light emitting layer with FIrpic phosphorescent materials doped with TPBi, to optimize the thickness of blue light emittinglayer, and to get white light device which has the max brightness of 23290 cd/m2, and max power efficiency of 9.27 lm/W. Finaly, inserting spacer layer TAPC to restrict the excition, and optimizing the thickness of spacer layer to improve the blue luminous intensity and got the max brightness of 26913 cd/m2, and max power efficiency of 13.28 lm/W near white lighting emitting device,eventually. The structure with charge control layer has a certain guiding role to the study of high efficiency white light device.