Organic Thin-Film Transistors Processed from Relatively Nontoxic, Environmentally Friendlier Solvents

Poly(2,6-bis(3-alkylthiophen-2-yl)dithieno- [3,2- b;2′,3′- d ]-thiophene)s represent a new class of solution-processable polymer semiconductors for organic thin-film transistors. This class of polymer semiconductors offers not only high field-effect transistor mobility, but also processability from relatively nontoxic, environmentally friendlier solvents. Thin-film transistors utilizing these polymer semiconductors fabricated even from environmentally friendlier organic solvents of generally low solvency such as hexane and toluene have exhibited high field-effect mobility and current on/off ratio as well as excellent thermal stability and high resistance to photoinduced oxidative doping. This is in sharp contrast to most high-mobility polymer semiconductors, which require toxic chlorinated aromatic solvents for fabrication to achieve high mobility. The use of relatively nontoxic processing solvent would eliminate the safety concerns associated with use of chlorinated aromatic solvents, potentially enabling low-cost mass manufacturing processes for thin-film transistor devices.