Impedance spectroscopy measurements of charge carrier mobility in 4,4′-N,N′-dicarbazole-biphenyl thin films doped with tris(2-phenylpyridine) iridium

被引：23

作者：

Ishihara, Shingo ^{[1
,2
,3
]}

Okachi, Takayuki ^{[1
]}

Naito, Hiroyoshi ^{[1
,2
]}

机构：

[1] Osaka Prefecture Univ, Dept Phys & Elect, Naka Ku, Osaka 5998531, Japan

[2] Osaka Prefecture Univ, Res Inst Mol Elect Devices, Naka Ku, Osaka 5998531, Japan

[3] Hitachi Ltd, Mat Res Lab, Hitachi, Ibaraki 3191292, Japan

来源：

THIN SOLID FILMS | 2009年 / 518卷 / 02期

关键词：

Organic light-emitting diodes; Impedance spectroscopy; Mobility; CBP; Ir(ppy)(3); LIGHT-EMITTING-DIODES; GREEN ELECTROPHOSPHORESCENT DEVICES; ADMITTANCE SPECTROSCOPY; EMISSIVE LAYER; TRANSPORT; VINYLENE); TRANSIENT;

D O I：

10.1016/j.tsf.2009.07.003

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The charge carrier mobility of green phosphorescent emissive layers, tris(2-phenylpyridine) iridium [Ir(ppy)(3)]-doped 4,4'-N,N'-dicarbazole-biphenyl (CBP) thin films, has been determined using impedance spectroscopy (IS) measurements. The theoretical basis of mobility measurement by IS rests on a theory for single-injection space-charge limited current. The hole mobilities of the Ir(ppy)(3)-doped CBP thin films were measured to be 10(-10)-10(-8) cm(2)V(-1)s(-1) in the 2-7wt.% Ir(ppy)(3)-doped CBP from the frequency dependence of both conductance and capacitance. These hole mobility values are much lower than those of the undoped CBP thin films (similar to 10(-3) cm(2)V(-1)s(-1)) because the Ir(ppy)(3) molecules act as trapping centers in the CBP host matrix. These mobility measurements in the Ir(ppy)(3)-doped CBP thin films provide insight into the hole injection process. (C) 2009 Elsevier B.V. All rights reserved.

引用

页码：452 / 456

页数：5

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