High-Performance Solution-Deposited Ambipolar Organic Transistors Based on Terrylene Diimides

The thin film transistor characteristics of a soluble molecular semiconductor, terrylene tetracarboxdiimide (TDI), a homologue of perylene tetracarboxdiimide (PDI), have been investigated. In a bottom-gate device structure with benzocyclobutene gate dielectric, n-type behavior with electron mobility of 1.1 × 10−2 cm2 V−1 s−1 has been observed after thermal annealing. When applied in the top-gate structure with a polycyclohexylethylene-based gate dielectric, TDI devices exhibit ambipolar transport with electron and hole mobility of 7.2 × 10−3 cm2 V−1 s−1 and 2.2 × 10−3 cm2 V−1 s−1 respectively. The correlation between morphology and field-effect mobility was investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD) studies. Spin-coated, annealed TDI film crystallize in a terrace structure, and the molecules are packed in an “edge-on” structure, thus forming a favorable packing arrangement for charge transport in the plane of the film.