Patterned graphene: Analysis of the electronic structure and electron transport by first principles computational modeling

Abstract

Patterned graphene could provide a useful platform for applications. We show here that, unlike graphene nanoribbons in which rough edges affect the transport, comparison of D and G Raman intensity peaks at the edge of the defective region of our patterned graphene indicates relatively small deterioration. Motivated by this observation, our goal is to understand the electronic properties and electron transport characteristics of patterned graphene comprised of alternating strips of pristine graphene and functionalized graphene with epoxide groups, in comparison to graphene nanoribbons. Analysis of the electronic structures demonstrates confinement of the Dirac electrons in the graphene strips, with varying bandgaps that depend on the strip’s width. Electron transport calculations predict similar intrinsic transport efficiency for patterned graphene and corresponding graphene nanoribbons. Upon introduction of realistic Au electrodes in device models, we show that the conductance reduces to ∼70% of the intrinsic response for graphene electrodes, potentially achieving minimal contact resistance, while gold electrodes with side- or end-contacts result in ∼20–30% reductions. Transport efficiency drops rapidly with a distance increase between electrode and patterned graphene in a side-contact setup. Our results will potentially motivate further characterization of patterned graphene.