Solvent-Dispersed Benzothiadiazole-Tetrathiafulvalene Single-Crystal Nanowires and Their Application in Field-Effect Transistors

A new organic semiconductor (BT-TTF) based on molecular moieties of benzothiadiazole and tetrathiafulvalene was designed and synthesized, and its structure, molecular packing and charge-transporting properties were determined. Thermal properties, electrochemical behaviors, and optical absorption of this molecule were studied by using differential scanning calorimetry/thermal gravimetric analysis, cyclic voltammetry, and ultraviolet-visible spectroscopy, respectively. Its bulk and nanowire single crystals were prepared and characterized by X-ray crystallography, scanning electron microscopy, transmission electron microscopy, and field-effect transistors. It is found that short intermolecular S···S (3.41 Å), S···C (3.49 Å), and S···N (3.05 Å) contacts define the solid-state structure of BT-TTF single crystals which π-stack along the [100] with interplanar distances of 3.49 Å. Solvent-cast single-crystal nanowire transistors showed mobilities as large as 0.36 cm²/(V s) with current on/off ratios of 1 × 10⁶. This study further illustrates the impact of molecular design and a demonstration of high-performance single-crystal nanowire transistors from the resulting semiconductor. © 2013 American Chemical Society.