Improved band alignment for hole injection by an interfacial layer in organic light emitting devices

被引：41

作者：

Chkoda, L ^{[1
]}

Heske, C ^{[1
]}

Sokolowski, M ^{[1
]}

Umbach, E ^{[1
]}

机构：

[1] Univ Wurzburg, D-97074 Wurzburg, Germany

来源：

APPLIED PHYSICS LETTERS | 2000年 / 77卷 / 08期

关键词：

D O I：

10.1063/1.1289804

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We demonstrate that a thin organic interfacial layer of 3,4,9,10 perylenetetracarboxylic dianhydride (PTCDA) can be utilized to improve the band alignment of N,N'-di-(3-methylphenyl)N,N'diphenyl-4,4'diaminobiphenyl (TPD) films on [indium-tin-oxide (ITO)] (InSnO) substrates in, e.g., organic electroluminescent devices. A photoemission study of the highest occupied molecular orbital (HOMO) and vacuum level position as a function of the organic overlayer thickness reveals that due to chemisorptive bonding a thin PTCDA interlayer results in a reduced barrier between the Fermi level of ITO and the HOMO of TPD. Furthermore we detect a new molecular state 0.6 eV below the Fermi level at the PTCDA/ITO interface. Both effects are expected to improve the hole injection from the ITO anode into the TPD hole transport layer, e.g., in organic light emitting devices. (C) 2000 American Institute of Physics. [S0003-6951(00)05134-2].

引用

页码：1093 / 1095

页数：3

共 19 条

[1]

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[2] ELECTROLUMINESCENCE FROM TRAP-LIMITED CURRENT TRANSPORT IN VACUUM-DEPOSITED ORGANIC LIGHT-EMITTING DEVICES [J].