Frequency Characteristics of Polymer Field-Effect Transistors with Self-Aligned Electrodes Investigated by Impedance Spectroscopy

Abstract

Solution-based organic field-effect transistors (OFETs) with low parasitic capacitance have been fabricated using a self-aligned method. The self-aligned processes using a cross-linking polymer gate insulator allow fabricating electrically stable polymer OFETs with small overlap area between the source-drain electrodes and the gate electrode, whose frequency characteristics have been investigated by impedance spectroscopy (IS). The IS of polymer OFETs with self-aligned electrodes reveals frequency-dependent channel formation process and the frequency response in FET structure. key words: organic field-effect transistors, frequency response, selfaligned method, impedance spectroscopy, cross-linking polymer insulators Hiroyoshi Naito received the B.E., M.E. and Dr.Eng. degrees from Osaka Prefecture University in 1979University in , 1981University in , and 1984 He is a Professor in the Department of Physics and Electronics, Osaka Prefecture University. He has been engaged in the photoelectric characterization of disordered semiconductors such as amorphous chalcogenide glasses and of liquid crystalline materials. His current interests are optical and electronic properties of organic semiconductors and their application to optoelectronic devices. Prof. Naito is a member of the Imaging

Interpretation of modulus spectra in organic field-effect transistors: equivalent-circuit approach

“…1. Unique techniques such as a self-alignment method [26][27][28] enable us to fabricate OFETs without the electrode overlap regions. However, the electrode overlap is essential to improve charge carrier injection from the source electrode and hence to improve the cut-off frequency as mentioned above.…”