Nanoscale contacts between semiconducting nanowires and metallic graphenes

Here we report on the metal–semiconductor junction characteristics of a semiconducting ZnO nanowire grown directly on a metallic graphene film. The extracted specific contact resistivity of the graphene–ZnO nanowire contact (1.5 × 10−5 Ω·cm2) is comparable to that reported for Al–ZnO contacts. Based on the assumption that thermionic-field emission is the dominant mechanism, we obtained a zero-bias effective barrier height of 0.413 eV for the graphene–ZnO nanowire Schottky contact. We thus demonstrate that as a result of the enhanced tunneling at the contact, the graphene–nanowire contact exhibits near-ohmic current–voltage characteristics with a low contact resistance.