Enhanced efficiency in single-host white organic light-emitting diode by triplet exciton conversion

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• 作者：Qingyang Wu ; Shiming Zhang ; Shouzhen Yue ; Zhensong Zhang ; Guohua Xie ; Yi Zhao ; Shiyong Liu
• 关键词：WOLED ; Single host ; EQE ; FIrpic ; PO-01 ; Co-dope
• 刊名：Journal of Luminescence
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：143
• 期：Complete
• 页码：108-112
• 全文大小：1335 K

文摘

The authors observe that the external quantum efficiency (EQE) of the Iridium (III) bis(4-phenylthieno [3,2-c]pyridinato-N,C^2¡ä)acetylacetonate (PO-01) based yellow organic light-emitting diode (OLED) is significantly increased by uniformly co-doping Iridium (III)bis[(4,6-difluorophenyl)-pyridinato-N,C^2?] (FIrpic) and PO-01 into the same wide band-gap host of N,N^¡ä-dicarbazolyl-3, 5-benzene (mCP). Detailed investigation indicates that the efficiency enhancement is ascribed to effective triplet exciton gathering by FIrpic, followed by energy transfer to PO-01. Compared to the control device, which has maximum EQE of 10.5 % , an improved maximum EQE of 13.2 % is obtained in the optimization white device based on FIrpic and PO-01 emission according to this principle. This work makes it easier for a single host white OLED to simultaneously harvest high efficiency in both blue and yellow units. Comprehensive experimental results show that this phenomenon can also be found and utilized in other popular hosts to realize more efficient white devices.