Band Gap Tuning of Hydrogenated Graphene: H Coverage and Configuration Dependence

The electronic states of partially hydrogenated graphene (HG) structures are studied by the density functional theory calculations. Several types of HG configurations, including randomly removing of H pair, randomly removing individual H atoms, and ordered H pairs removal, are investigated. We find that the configurations with randomly removing H pairs are most energetically favorable. More interestingly, the band gap for such configurations decrease with H concentration and approaches zero around 67% H coverage. The ability to continuously tune the band gap of hydrogenated graphene from 0 to 4.66 eV by different H coverage provides a new pathway for engineering the electronic structure of graphene materials and enhances their applications in electronics and photonics.