Organic Dipole Layers for Ultralow Work Function Electrodes

被引:107
作者
Ford, William E. [1 ]
Gao, Deqing [1 ]
Knorr, Nikolaus [1 ]
Wirtz, Rene [1 ]
Scholz, Frank [1 ]
Karipidou, Zoi [1 ]
Ogasawara, Kodo [1 ]
Rosselli, Silvia [1 ]
Rodin, Vadim [1 ]
Nelles, Gabriele [1 ]
von Wrochem, Florian [1 ]
机构
[1] Sony Deutschland GmbH, Mat Sci Lab, D-70327 Stuttgart, Germany
关键词
molecular dipole; self-assembled monolayer; injection barrier; organic electronics; work function; interface dipole; SELF-ASSEMBLED MONOLAYERS; LIGHT-EMITTING-DIODES; ENERGY-LEVEL ALIGNMENT; CONJUGATED POLYMER; METAL; TOP; ENERGETICS; INTERFACE; DEVICES; GOLD;
D O I
10.1021/nn502794z
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The alignment of the electrode Fermi level with the valence or conduction bands of organic semiconductors is a key parameter controlling the efficiency of organic light-emitting diodes, solar cells, and printed circuits. Here, we introduce a class of organic molecules that form highly robust dipole layers, capable of shifting the work function of noble metals (Au and Ag) down to 3.1 eV, that is, similar to 1 eV lower than previously reported self-assembled monolayers. The physics behind the considerable interface dipole is elucidated by means of photoemission spectroscopy and density functional theory calculations, and a polymer diode exclusively based on the surface modification of a single electrode in a symmetric, two-terminal Au/poly(3-hmIthiophene)/Au junction is presented. The diode exhibits the remarkable rectification ratio of similar to 2 center dot 10(3) showing high reproducibility, durability (>3 years), and excellent electrical stability. With this evidence, noble metal electrodes with work function values comparable to that of standard cathode materials used in optoelectronic applications are demonstrated.
引用
收藏
页码:9173 / 9180
页数:8
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