Synthesis and Characterization of Novel Semiconductors Based on Thieno[3,2-b][1]benzothiophene Cores and Their Applications in the Organic Thin-Film Transistors

The synthesis and characterization of four new organic semiconductors with thieno[3,2-b][1]benzothiophene cores and different pi-bridge spacers are reported. Cyclic voltammetry measurement indicates that the materials have low energy levels of the highest occupied molecular orbitals and large band gaps. The single-crystal X-ray diffraction experiment reveals that 1,2-di(thieno [3,2-b][1]benzothiophenic-2-)ethylene (DTBTE) molecules have a nearly coplanar structure and crystallize into a herringbone arrangement with strongly intermolecular multiple S center dot center dot center dot S, S center dot center dot center dot C, and CH center dot center dot center dot pi interactions. These interactions facilitate charge carrier transport. The DTBTE-based organic thin-film transistors (OTFTs? on an octyltrichlorosilane-modified SiO(2)/Si substrate exhibit good field-effect performance with the highest mobility of 0.50 cm(2) V(-1) s(-1). Furthermore, the DTBTE-based OTFTs have been fabricated on a flexible polyethylene terephthalate substrate and showed a maximum mobility of up to 0.45 cm(2) V(-1) s(-1), indicating its potential application as an organic semiconductor in the flexible OTFTs.