Abstract
We report on a thiol-based self-assembled monolayer treatment of the source/drain electrodes to improve the characteristics of an organic thin-film transistor with a bottom-contact configuration. With the treatment of immersing the substrate in octadecanethiol solution for 1 minute, the field effect mobility increases by 25% and the off current decreases about one order of magnitude compared to that without the treatment. It has been confirmed that thiol molecules absorbs in lying-down phase on the source/drain electrodes. A self-assembled monolayer in lying-down phase between the electrodes and a semiconductor plays an important role to reduce resistance at the interface without increase of the Schottky and tunneling barrier height.