A structurally simple but high-performing donor–acceptor polymer for field-effect transistor applications

A straightforward synthesis is reported for four structurally simple donor–acceptor conjugated polymers based on an alkylated difluorobenzotriazole and either unsubstituted bithiophene (T2) or thienylvinylthiophene (TVT) co-monomers. Two solubilizing sidechains are investigated in which the position of the branching point is moved away from the conjugated backbone. Optoelectronic measurements and density functional theory calculations show very similar energetic properties between the polymers, with a slightly narrower bandgap for the vinylene incorporating TVT polymers as a result of extended conjugation. Transistor measurements demonstrate that the simplest polymer, containing a readily available 2-decyltetradecyl sidechain with a T2 co-monomer, exhibits the best device performance, with an average saturated mobility of 0.2 cm² V⁻¹ s⁻¹.