Band-Gap Engineering with Hybrid Graphane-Graphene Nanoribbons

The electronic structures of graphane nanoribbons and hybrid graphane-graphene nanoribbons were investigated using the first-principles method. Energy gaps of both zigzag and armchair graphane nanoribbons were found to increase as the nanoribbons become narrower. The hybrid graphane-graphene nanoribbons show structure dependence and tunable electronic properties. The band gap of armchair hybrid nanoribbons is dominated by its graphene section, whereas a spin-split defect level emerges in the band gap of zigzag hybrid nanoribbons, which depends on the hydrogenation of the graphane-graphene interface zigzag carbon chain. These findings provide a basis for achieving band gap engineering and controllable spin filters based only on light elements.