Reversible Conversion of the Majority Carrier Type in Solution-Processed Ambipolar Quinoidal Oligothiophene Thin Films

Solution-processed organic field-effect transistors based on the ambipolar quinoidal oligothiophene [QQT(CN)4] show either p- or n-type dominant behavior depending on the solvent used for the spin-coating of the semiconducting organic thin film. In addition, majority carrier type conversion from n-type to ambipolar is achieved by solvent vapor treatment.