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 0.1–1cm2∕Vs. 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 60meV. 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.