Two-dimensional Graphene Superlattice Made with Partial Hydrogenation

Electronic properties of two-dimensional graphene superlattice made with partial hydrogenation were thoroughly studied via Density Functional Tight Binding approach (DFTB) which incorporates the tight-binding method into the density functional formalism. The two-dimensional (2-d) pattern of hydrogen atoms on graphene was found to have great effects on electronic structures of graphene superlattice. In particular, the edges of the 2-d pattern, armchair or zigzag, are essential for the energy band gap opening, and the energy band gap sensitively depends on the shape, size, and the 2-d periodicity of the pattern. Based on these findings, we suggested that the 2-d graphene superlattice may be used in fabricating quantum dots and 2-d heterojunctions on graphene without the need for cutting or etching.