Symmetry-dependent electronic structure transition in graphether nanoribbons

Abstract

Graphether, a two-dimensional oxocarbon monolayer, has attracted wide attention due to its excellent mechanical, thermal, and electrical performance. Armchair-edged graphether nanoribbons (AGENRs) are investigated through first-principles calculations. It is found that symmetry plays a key role in band structures, which could trigger an indirect–direct transition of the bandgap, following the odd–even parity of the nanoribbon. Furthermore, the asymmetrical electronic structure caused by edge hydrogen passivation would induce semiconducting–metallic transition. Our findings imply that the electronic structure properties of AGENRs could be modulated by symmetry, which may throw light on the band engineering of related devices and the design of heterostructures.