Exciplex-Forming Co-host for Organic Light-Emitting Diodes with Ultimate Efficiency

被引：459

作者：

Park, Young-Seo ^{[1
,2
]}

Lee, Sunghun ^{[3
]}

Kim, Kwon-Hyeon ^{[2
,3
]}

Kim, Sei-Yong ^{[1
,2
]}

Lee, Jeong-Hwan ^{[2
,3
]}

Kim, Jang-Joo ^{[1
,2
,3
]}

机构：

[1] Seoul Natl Univ, Dept Mat Sci & Engn, Seoul 151744, South Korea

[2] Seoul Natl Univ, Ctr Organ Light Emitting Diode, Seoul 151744, South Korea

[3] Seoul Natl Univ, Dept Mat Sci, WCU Hybrid Mat Program, Seoul 151744, South Korea

来源：

ADVANCED FUNCTIONAL MATERIALS | 2013年 / 23卷 / 39期

关键词：

exciplexes; co-hosts; energy transfer; efficiency roll-off; organic light emitting diodes;

D O I：

10.1002/adfm.201300547

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Phosphorescent organic light-emitting diodes (OLEDs) with ultimate efficiency in terms of the external quantum efficiency (EQE), driving voltage, and efficiency roll-off are reported, making use of an exciplex-forming co-host. This exciplex-forming co-host system enables efficient singlet and triplet energy transfers from the host exciplex to the phosphorescent dopant because the singlet and triplet energies of the exciplex are almost identical. In addition, the system has low probability of direct trapping of charges at the dopant molecules and no charge-injection barrier from the charge-transport layers to the emitting layer. By combining all these factors, the OLEDs achieve a low turn-on voltage of 2.4 V, a very high EQE of 29.1% and a very high power efficiency of 124 lm W-1. In addition, the OLEDs achieve an extremely low efficiency roll-off. The EQE of the optimized OLED is maintained at more than 27.8%, up to 10 000 cd m(-2).

引用

页码：4914 / 4920

页数：7