Ambipolar field-effect transistor (FET) and redox characteristics of a π-conjugated thiophene/1,3,4-thiadiazole CT-type copolymer

A pi-conjugated charge transfer-type copolymer consisting of an electron-donating thiophene and an electron-accepting 1,3,4-thiadiazole, P(ThdzTh), underwent facile electrochemical p- and n-doping, as revealed by cyclic voltammetry. The copolymer gave a new ambipolar field-effect transistor (FET), which showed typical I-DS (source-drain current)-V-DS (source-drain voltage) curves in both a p-type working mode and an n-type working mode. In the n-type working mode, the polymer showed a carrier mobility of about 5 x 10(-3) cm(2) center dot V-1 center dot s(-1) and an on/off ratio of about 3 x 10(4).