The effects of the surface morphology of poly(3,4-ethylenedioxythiophene) electrodes on the growth of pentacene, and the electrical performance of the bottom contact pentacene transistor

An investigation is presented of the effect of the surface roughness of poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes on the growth of pentacene and the electrical performance of PEDOT electrode bottom contact pentacene transistor. Smooth PEDOT films contained well-oriented and small sized pentacene islands whilst rough PEDOT films exhibited randomly oriented islands with non-uniformly sized islands. In addition, PEDOT electrodes provided morphological continuity at the electrode–channel interface, making the accumulation channel of the pentacene formed on the electrodes a main contributor to the contact resistance. Accordingly, the smooth PEDOT surface yielded the low contact resistance (5.7 kΩ cm), approximately half of that obtained with the rough surface.

► Smooth PEDOT films produced well-oriented pentacene islands whilst rough PEDOT films yielded randomly-oriented islands.
► PEDOT electrodes provided morphological continuity at the electrode–channel interface.
► The accumulation channel formed on the electrodes can be a main contributor to the contact resistance.
► The smooth PEDOT surface yielded the low contact resistance.