Improved Contact Properties for Organic Thin-Film Transistors Using Self-Assembled Monolayer

Contact properties between the organic semiconductor and the metal source and drain contacts are one of the most important issues since the charge carrier injection through the contact has serious effects on the device performance. In this study, gold (Au) surfaces of the source and drain electrodes are modified using self-assembled monolayers (SAMs) using thiol derivatives. The charge carrier mobility was increased from 0.1 to 0.48 cm2/Vs after the modification of the source and drain electrodes. Mobilities and saturation currents seem to be governed more effectively by the contact properties than by the work function difference between the (modified) electrodes and organic semiconductor.