Electronic and structural properties of tetragraphenes

Abstract

The search for targeted modifications of graphene to tune its electronic properties has stimulated the proposal of several new allotropic variations of carbon with sp and sp2 hybridizations. In this study, a class of 2-dimensional carbon nanostructures with mixed sp2−sp3 hybridization is theoretically investigated. These structures contain hexagonal and tetragonal cycles and are shown to exhibit metallic or semiconducting behaviors depending on structural parameters. The key for the manipulation of the physical properties is the extent of the system’s graphene-like section. Remarkable properties emerge, such as Dirac cones, which are allowed by the coupling between different sectors of the system as mediated by tetrahedrally-coordinated carbon atoms. In addition to fundamental properties, we also point aspects suggesting the experimental feasibility of these systems.