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 WO
3
/Au electrodes. We have obtained that the performance and the field-effect mobility of the devices with bilayer WO
3
/Au electrode was highly improved by comparing with pentacene based transistor without WO
3
layer. The field-effect mobility was increased from 0.47 cm
²
/Vs to 0.69 cm
²
/Vs in the device with bilayer WO
3
/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.