In-plane conductance measurement of graphene nanoislands using an integrated nanogap probe

The in-plane conductance of individual graphene nanoislands thermally grown on SiC substrate was successfully measured using an integrated nanogap probe without lithographic patterning. A Pt nanogap electrode with a 30 nm gap integrated on the cantilever tip of a scanning probe microscope enables us to image a conductance map of graphene nanoislands with nanometer resolution. Single- and double-layer graphene islands are clearly distinguished in the conductance image. The size dependence of the conductance of the nanoislands suggests that the band gap opening is due to the lateral confinement effect.