Thin-film morphologies and solution-processable field-effect transistor behavior of a fluorene-thieno[3,2-b]thiophene-based conjugated copolymer

A fluorene- and thienol[3,2-b]thiophene-based copolymer suitable for use as semiconducting materials in solution-processable organic field-effect transistors were synthesized. Replacement of the flexible bithiophene in F8T2 with a rigid fused thieno[3,2-b]thiophene yielded a polymer (F8TT) with higher crystallinity and an ordered morphology. Improvements in the performances of TFTs based on F8TT should be possible by the optimization of the fabrication conditions and/or the alignment technique for molecular orientation. The study provides valuable information on the relationship between the molecular structure of a semiconducting material and its electrical performance in thin film electronic devices.