A solution-processable dicyano-substituted quinoidal oligothiophene for air-stable ambipolar organic field-effect transistors

Abstract

A novel solution-processable dicyano-substituted quinoidal oligothiophene molecule CDT-2T(CN)4 was synthesized and characterized. CDT-2T(CN)4 displayed high thermal stability and broad thin film absorption in the near IR region. Electrochemical results showed that CDT-2T(CN)4 exhibited reversible oxidation and reduction peaks with the LUMO energy level at −4.2 eV and the HOMO energy level at −5.3 eV. The solution processed thin film transistors of CDT-2T(CN)4 displayed electron-dominant ambipolar transport behavior under ambient conditions. The optimal saturation hole and electron mobilities were 0.003 and 0.023 cm² V⁻¹ s⁻¹, respectively, one of the highest values for solution processed quinoidal based ambipolar organic semiconductors with good ambient stability.