Patterning graphene nanoribbons using copper oxide nanowires

We present a fabrication technique for graphene nanoribbons (GNRs) that employs copper oxide nanowires as the etch masks. We demonstrate that these etch masks have numerous advantages: they can be synthesized simply by heating a copper foil in air, deposited on graphene from a solution, they are inert to oxygen plasma, and can be removed from the substrate by dissolution in mild acids. We fabricated GNRs in the device configuration and tested their electrical properties. Depending on the duration of the plasma etching, GNR devices exhibiting either standard ambipolar electric field effects or p-type transistor behaviors with ON-OFF ratios 50 can be fabricated. The resulting devices based on narrow GNRs are demonstrated to exhibit promising electronic properties, which can be exploited in studies where GNR devices are required.