All-organic field effect transistors

In this work we present fully patterned organic transistors based on selective electropolymerization of conducting polymers that enables simple fabrication of micron scale features. It involves fabrication of pentacene field effect transistors in which the conducting, insulating parts as well as the substrate are all made of polymers. We have fabricated drain and source electrodes by electropolymerization of 3,4- ethylenedioxythiophene and gate by spin coating of commercially available poly( 3,4- ethylenedioxythiophene) (PEDOT:PSS) aqueous dispersion, polyvinylalcohol for the gate dielectric layer, and pentacene for the organic active layer. We have built a top-gate structure with gate dielectric layer and gate placed on the top of the pentacene layer, and in a such way obtained protection of the active layer could permit enhancement of the operating time of devices. Carrier mobility as large as 0,01 cm2/V s was measured. Functional all- organic transistors have been realised using a simple and potentially inexpensive technology.