Synthesis of edge-closed graphene ribbons with enhanced conductivity.

Edge-closed and edge-opened graphene ribbons were synthesized on Pd nanowire templates using plasma-enhanced chemical vapor deposition (PECVD). After metal nanowire etching, the tubular shaped thin graphene layers were collapsed to edge-closed graphene ribbon. In order to make edge-opened graphene ribbons, the graphene layers on the top part of the metal nanowire were selectively etched by O(2) plasma. The protected graphene layers at the bottom of nanowire are transformed to edge-opened graphene ribbon after nanowire etching. Because of defect-free edges, edge-closed graphene ribbon showed reduced D-band intensity compared to edge-opened graphene ribbons, and moreover, the conductivity of edge-closed graphene ribbon was much higher than that of edge-opened graphene ribbon.