2-Thiopene[1]benzothieno[3,2-b]benzothiophene derivatives as solution-processable organic semiconductors for organic thin-film transistors

Novel [1]benzothieno[3,2-b]benzo-thiophene (BTBT) derivatives were synthesized and characterized as solution-processable organic semiconductors for top-contact/bottom-gate organic filed-effect transistors (OFETs). Physicochemical properties of the new compounds were characterized by UV-vis absorption spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), cyclic voltammetry (CV), and density functional theory (DFT) calculation. The electrical properties of the corresponding compounds were investigated through the fabrication and characterization of field-effect transistors via solution-shearing. Both compounds were FET active and exhibited decent p-channel activity with carrier mobilities up to 0.10 cm2 V−1 s−1 and current on/off ratio >108. Film morphology and microstructure, as characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD) were correlated with the device performance.