Influence of 2-mercapto-5-nitrobenzimidazole treatment on the electronic characteristics of bottom-contact organic field-effect transistors

The treatment of the Au electrodes of an organic bottom-contact thin film transistor with 2-mercapto-5-nitrobenzimidazole (MNB) led to improved current-voltage characteristics. X-ray diffraction, atomic force microscopy, soft X-ray emission spectroscopy, and ultraviolet photoelectron spectroscopy were used to investigate the structure-function relationship in the device components MNB and pentacene. By treating the Au contacts with MNB prior to the pentacene deposition, the morphological and structural properties of the pentacene come to resemble the ideal case of pentacene deposited onto SiO₂. The action of the MNB is therefore to remove the transition region at the Au/pentacene interface, leading to improved charge carrier injection.