Solution-processed organic field-effect transistors based on polythiophene derivatives with conjugated bridges as linking chains

A study was conducted to demonstrate the synthesis of solution-processed organic field-effect transistors (OFET) based on polythiophene derivatives (PT) with conjugated bridges as linking chains. Two novel PTs, vinylene-thienylene- vinylene-thieneylene-vinylene (PT-VTVTV2 and PT-VTVTV4) were synthesized, with conjugated bridges as linking chains. Their optical, thermal properties, and field-effect characteristics were also studied. The synthesis of PT-VTVTV2 and PT-VTVTV4 were achieved by Stille coupling reaction by adding different ratios of the monomer A as seed. The monomer A was synthesized by Wittig-Hornor reaction and the regioregularities of PT-VTVTV2 and PT-VTVTV4 were found to be 70% and 69%, which were calculated from the ratio of the integral area of the two peaks at 2.5-2.8 ppm in the H NMR spectra. The structure order and crystallization of the two polymers were also investigated by film X-ray diffraction (XRD) and atomic force microscopy (AFM).