Graphene nanomeshes: Onset of conduction band gaps

Huckel simulations of large finite graphene nanomeshes with lithographically induced holes show sizable band gaps in the conduction while the optical absorption has generally the same semi-metal character as pure graphene. There is a strong dependence of the band gap on the angle between the graphene axis and the periodic hole axis. Simple modification of on-site energies shows that substituents on the edges of the holes could also have a significant effect. These simulations show that graphene nanomeshes, which have been recently fabricated, are potentially useful tunable materials for electronic applications.