Impedance Spectroscopy and Equivalent Circuits of Conductively Doped Organic Hole-Transport Materials
Journal
Organic Electronics
Journal Volume
11
Journal Issue
12
Pages
1901-1908
Date Issued
2010-12
Author(s)
Chung-Chia Chen
Bo-Chao Huang
Ming-Shiang Lin
Yin-Jui Lu
Ting-Yi Cho
Chih-Hao Chang
Kun-Cheng Tien
Su-Hao Liu
Tung-Hui Ke
Abstract
In this work, the impedance spectroscopy was adopted to characterize conductively doped organic hole-transport layers. We performed comparative studies of the impedance spectroscopy of undoped and doped hole-transport materials, by both experiment and simulation approaches. The impedance spectroscopy of the non-doped hole-transport material can be well understood by simply adopting the conventional RC equivalent circuits and considering the dielectric response frequency-independent. For the conductively doped organic hole-transport materials, however, successful modeling of the impedance spectroscopy results need to take into account the more complicated situations: including the difference between the bulk region and the depletion region near the electrode, and dispersion (i.e. frequency dependence) in the dielectric response of the conductively doped transport layer. As such, it is found necessary to include the complex dielectric response and the non-conventional complex impedance element in the equivalent circuit to achieve tight matching of simulated results with experiment results over wide bias and frequency ranges. © 2010 Elsevier B.V. All rights reserved.
Type
journal article