Formation of Bandgap and Subbands in Graphene Nanomeshes with Sub-10 nm Ribbon Width Fabricated via Nanoimprint Lithography

We fabricated hexagonal graphene nanomeshes (GNMs) with sub-10 nm ribbon width The fabrication combines nanoimprint lithography, block-copolymer self-assembly for high-resolution nanoimprint template patterning, and electrostatic printing of graphene Graphene field-effect transistors (GFETs) made from GNMs exhibit very different electronic characteristics in comparison with unpatterned GFETs even at room temperature We observed multiplateaus in the drain current gate voltage dependence as well as an enhancement of ON/OFF current ratio with reduction of the average ribbon width of GNMs These effects are attributed to the formation of electronic subbands and a bandgap in GNMs Such mesoscopic graphene structures and the nanofabrication methods could be employed to construct future electronic devices based on graphene superlattices