title: Formation of bandgap and subbands in graphene nanomeshes with sub-10 nm ribbon width fabricated via nanoimprint lithography.
abstract: 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.
authors.affiliation: Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. xliang@lbl.gov
authors.forename: Xiaogan
authors.initials: X
authors.lastname: Liang
authors.forename: Yeon-Sik
authors.initials: YS
authors.lastname: Jung
authors.forename: Shiwei
authors.initials: S
authors.lastname: Wu
authors.forename: Ariel
authors.initials: A
authors.lastname: Ismach
authors.forename: Deirdre L
authors.initials: DL
authors.lastname: Olynick
authors.forename: Stefano
authors.initials: S
authors.lastname: Cabrini
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bokor