Linear benzene-fused bis(tetrathiafulvalene) compounds for solution processed organic field-effect transistors

Abstract

Three new linear benzene-fused bis(tetrathiafulvalene) compounds (4–6) were synthesized and characterized. Compounds 4 and 5, comprising branched alkyl chains (2-ethylbutyl and 2-ethylhexyl, respectively), had very good solubility in common organic solvents and were successfully used as p-channel semiconductors in solution-processed organic field-effect transistors (FET). The FET device based on 5 showed a mobility of 5.6 × 10^–4 cm² V^–1 s^–1 with an on/off ratio of 1.6 × 10⁴, and the devices based on 4 and 5 displayed good reproducibility in air. In addition, 6, bearing the long n-dodecyl chains, exhibited self-assembly behavior; one-dimensional self-assembly micron-scale ribbons formed in solution and were revealed by scanning electron microscopy on SiO₂ substrates.