Enhancement of electron injection in organic light-emitting devices using an Ag/LiF cathode

被引:70
作者
Wang, XJ [1 ]
Zhao, JM [1 ]
Zhou, YC [1 ]
Wang, XZ [1 ]
Zhang, ST [1 ]
Zhan, YQ [1 ]
Xu, Z [1 ]
Ding, HJ [1 ]
Zhong, GY [1 ]
Shi, HZ [1 ]
Xiong, ZH [1 ]
Liu, Y [1 ]
Wang, ZJ [1 ]
Obbard, EG [1 ]
Ding, XM [1 ]
Huang, W [1 ]
Hou, XY [1 ]
机构
[1] Fudan Univ, Inst Adv Mat, Surface Phys Lab, Natl Key Lab, Shanghai 200433, Peoples R China
关键词
D O I
10.1063/1.1655676
中图分类号
O59 [应用物理学];
学科分类号
摘要
A LiF-buffered silver cathode has been used in organic light-emitting devices (OLEDs) with structure indium-tin-oxide/N,N'-bis-(1-naphthl)-diphenyl-1,1'-biphenyl-4,4'-diamine (50 nm)/Alq(3) (100 nm)/cathode. The efficiency of electron injection from the cathode is strongly dependent on the thickness of the LiF buffer layer. While a LiF layer thinner than 1.0 nm leads to higher turn-on voltage and decreased electroluminescent (EL) efficiency, a LiF layer of 3.0 nm significantly enhances the electron injection and results in lower turn-on voltage and increased EL efficiency. A brightness of 16 000 cd/m2 and EL efficiency of 4.8 cd/A can be achieved with an Ag/LiF cathode. This dependence of electron injection on the LiF thickness is quite different from that reported for OLEDs with a Al/LiF cathode, but can be well understood using the tunneling model. (C) 2004 American Institute of Physics.
引用
收藏
页码:3828 / 3830
页数:3
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