Maxwell-Wagner model analysis for the capacitance-voltage characteristics of pentacene field effect transistor

The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of pentacene field effect transistors (FETs) were examined to clarify channel formation in conjunction with the UV/ozone treatment of the source and drain metal (Au) electrodes. Analyzing the I-V and C-V characteristics of FETs using the Maxwell-Wagner model showed that the main charge carriers in the FET channel are holes injected from the source, and that a pentacene FET with a UV/ozone-treated substrate shows a high effective mobility owing to holes smoothly injected into the FET channel. Furthermore, the pentacene film thickness dependence on FET characteristics showed that a channel sheet with a thickness less than 20 nm is formed at the pentacene/SiO2 interface. Finally, the employment of the Maxwell-Wagner model for the analysis of the C-V characteristics was shown to give good approximation even when taking into account the presence of a charge sheet at the interface.