Improved performance of top contact organic thin film transistors with bilayer WO3/Au electrodes

We have fabricated a top contact pentacene-based organic thin-film transistors (OTFTs) with bi-layer WO₃/Au electrodes. We have obtained that the performance and the field-effect mobility of the devices with bilayer WO₃/Au electrode was highly improved by comparing with pentacene based transistor without WO₃ layer. The field-effect mobility was increased from 0.47 cm²/Vs to 0.69 cm²/Vs in the device with bilayer WO₃/Au electrodes. From temperature dependence characteristics and surface morphology of pentacene, the improved device performance was due to the reduction in barrier height and surface roughness after inserting a suitable transitions metal oxide layer between the pentacene and the gold electrodes.