Single-crystal organic field-effect transistors based on dibenzo-tetrathiafulvalene

We report on the fabrication and characterization of field-effect transistors based on single crystals of the organic semiconductor dibenzo-tetrathiafulvalene (DB-TTF). We demonstrate that it is possible to prepare very-good-quality DB-TTF crystals from solution. These devices show high field-effect mobilities typically in the range $0.1–1{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s}$ . The temperature dependence was also studied revealing an initial increase of the mobility when lowering the temperature until it reached a maximum, after which the mobility decreased following a thermally activated behavior with activation energies between 50 and $60\mathrm{meV}$ . Calculations of the molecular reorganization energy and intermolecular transfer integrals for this material were also performed and are in agreement with the high mobility observed in this material.