Tetrathienoacene Copolymers As High Mobility, Soluble Organic Semiconductors

摘要

The development of polymer thin film transistors is viewed as a critical enabling step for the realization of large-area, mechanically flexible electronics. Extensive studies have been carried out on soluble thiophene polymers, in which a semiconducting thiophene backbone is functionalized with alkane side groups to enhance solubility. Regioregular poly(3-hexylthiophene) (P3HT) has emerged as the benchmark for this class of materials. The regioregularity of the alkyl chains allows the chains to pack more efficiently in the solid-state compared to their regiorandom analogues, leading to field-effect hole mobilities up to 0.1 cm~2/V·s. However, regioregularity also leads to longer effective conjugation lengths and P3HT can be easily oxidized in air because of its low ionization potential and can undergo photoinduced oxidation due to its small HOMO-LUMO band gap.