Ambipolar field-effect transistors based on solution-processable blends of thieno[2,3-b]thiophene terthiophene polymer and methanofullerenes

The surface-engineering techniques which can facilitate balanced ambipolar transport with high charge-carrier mobility in a blend of a terthiophene polymer with methanofullerene solution-processed into thin-film FET structures, were analyzed. It is found that amine-terminated silane monolayer leads to enhanced electron transport and low hole transport, with a positive-carrier-accumulation onset voltage of about -16 V. CMOS-like inverters have been built on a single substrate using two identical transistors with a channel length of 10 μ m. The results show that ambipolar blends of theino-[2,3-b]thiophene terthiophene polymer and PCBM were processed into thin-film field-effect transistors showing n- and p-type conduction under different bias conditions.