Field-effect transistors based on a polycyclic aromatic hydrocarbon core as a two-dimensional conductor

Hexabenzocoronene (HBC) derivatives which are designed to self-assemble into a two-dimensional conductor have been synthesized. The derivatives were deposited by vacuum sublimation as an active layer in organic field-effect transistors. The dihexyl and tetrahexyl derivatives increased the field-effect mobilities and on/off ratios by a factor of 10 or more as compared to the unsubstituted hexabenzocoronene and the hexahexyl derivative. This good performance could be explained by the self-assembly in a two-dimensional conductor of the HBC derivatives, i.e., the dihexyl and tetrahexyl derivatives, in contrast to the self-assembly in the one-dimensional conductor of the hexahexyl derivative and low self-assembling property of the unsubstituted HBC. (C) 2005 American Institute of Physics.