Study of Carrier Transport by Pentacene Thin-Film Transistors at High Temperatures

Abstract

In this study, the interface properties of pentacene organic thin-film transistors (OTFTs) were analyzed at elevated temperatures. The pentacene layers were deposited on the poly(α-methyl styrene) (PMS)-treated SiO2 dielectric layers. The threshold voltages (Vt) were varied drastically in the temperature range from 100 to 200 °C due to the phase transition of the PMS layer after the Tg point (TgPMS=76 °C). After high temperature electric measurements, the deformation of pentacene was observed using atomic force microscopy and the oxidation of pentacene was also observed in the fourier transform infrared spectroscopy (FTIR) (about 80 °C) by the appearance of C=O bonds. The drastic decrease in mobility of pentacene OTFTs about 100 °C was attributed to the distortion of the pentacene conjugate structure.