Reducing the contact resistance in bottom-contact-type organic field-effect transitors using an AgOx interface layer

Abstract

Bottom-contact organic field-effect transistors (OFETs) are prepared by inserting an AgOx layer between a pentacene layer and the source–drain electrodes. The contact resistance in the device is ∼8.1 kΩ·cm with an AgOx layer oxidized for 60 s but reaches 116.9 kΩ·cm with a non-oxidized Ag electrode. The drain current and mobility in the OFETs with the AgOx layer increase with the oxidization time and then gradually plateau, and this trend strongly depends on the work function of the Ag surface. Further, the hole injection is enhanced by the presence of Ag2O but inhibited by the presence of AgO.