Solution-processable end-functionalized tetrathienoacene semiconductors: Synthesis, characterization and organic field effect transistors applications

A series of dialkylated tetrathienoacene (TTAR)-based solution-processable small molecular organic semiconductors have been synthesized and characterized for organic field effect transistor (OFET) applications. The central dialkylated TTAR moiety was end-capped with thiophenylvinylthiophene (TVT), bithiophene (bT), and thienothiophene (TT) to afford new π-conjugated p-type active materials, DTVT-TTAR (1), DbT-TTAR (2), and DTT-TTAR (3), respectively. The physical and electrochemical properties and theoretical calculations as well as OFETs performance and thin film morphologies and microstructures of these new soluble TTARs are systematically studied. Using a solution-shearing method, DTVT-TTAR exhibits p-channel transport with the highest mobility of up to 0.18 cm² V⁻¹s⁻¹ and current ON/OFF ratios of 10⁴-10⁶, which is one of the highest hole mobilities for the solution-processed TTAR-based small molecules.