Functionalized anthradithiophenes for organic field-effect transistors

Two new semiconductors for organic thin-film transistors (OTFTs), diperfluorophenyl anthradithiophene (DFPADT) and dimethyl anthradithiophene (DMADT), have been synthesized and characterized. The first material exhibits ambipolar transport in OTFT devices with field-effect mobilities (μ) of 6 × 10⁻⁴ cm² V⁻¹ s⁻¹ and 0.05 cm² V⁻¹ s⁻¹ for electrons and holes, respectively. Therefore, diperfluorophenyl substitution was found to be effective to induce n-type transport. Dimethyl-substituted anthradithiophene (DMADT) was also synthesized for comparison and exhibited exclusively hole transport with carrier mobility of 0.1 cm² V⁻¹ s⁻¹. Within this semiconductor family, OTFT carrier mobility values are strongly dependent on the semiconductor film growth conditions, substrate deposition temperatures, and gate dielectric surface treatment.