Performance Enhancement of Organic Thin-Film Transistors with C60/Au Bilayer Electrode

Abstract

In this paper, we report the improvements in electrical properties of organic thin-film transistors (OTFTs) with a C60 buffer layer between pentacene and Au electrodes. We compared the electrical properties of OTFTs with a thin C60 buffer layer and those without any buffer layer. The mobility increased from 0.147 to 0.364 cm2/(V·s) for the device with a 15-Å-thick C60 layer. We also estimated contact resistance and found that the improved hole injection arose from the reduction in contact resistance owing to the presence of the C60 buffer layer. In addition, the threshold voltage decreased from -5 to about 0 V. We considered that the insertion of the C60 buffer layer reduced the intensity of an interface dipole, which brought about the improvements in the overall electrical properties including contact resistance.