Synthesis, characterization, and field-effect transistor performance of poly[2,6-bis(3-tridecanoxythiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene]

A new copolymer of benzo[1,2-b:4,5-b′]dithiophene and 3,3′-bis(tridecanoxy)-5,5′-bithiophene was synthesized through Stille copolymerization. The bis-(3-alkoxythiophene) monomer was synthesized through a silver fluoride mediated, palladium-catalyzed cross-coupling, in which bromide functional groups were preserved instead of consumed. The copolymer has been characterized and applied in field-effect transistors, giving a hole mobility of 2 x 10⁻³ cm²/Vs and an on/off ratio >10⁶, with negligible hysteresis, on standard silicon substrates.