Fully patterned all-organic thin film transistors

We have fabricated fully patterned all-organic thin film transistors on glass substrates using the conducting polymer poly(3,4-ethylenedioxythiophene) for the gate electrodes and the source and drain contacts, poly-4-vinylphenol for the gate dielectric layer, and pentacene or poly-3-hexylthiophene for the organic active layer. All-organic pentacene transistors have carrier mobility as large as 0.1 cm2/V s and threshold voltage of 1 V, similar to pentacene transistors fabricated with high-quality inorganic gate dielectrics and noble-metal contacts. The carrier mobility of all-polymer poly-3-hexylthiophene transistors is somewhat lower compared with that of pentacene transistors, but similar to that of poly-3-hexylthiophene devices made with inorganic metals and dielectrics.