Electronic Structure and Charge Transport in Nanostripped Graphene

An attractive strategy to generate semiconducting graphene layers is delineating rows of sp³ defects along the armchair direction that disrupt the π-conjugation and result in the formation of nanostripped structures with tunable band gap. This is investigated here using density functional theory (DFT) calculations, where we have assessed how much the electronic structure of the nanostructured graphene layers is affected by the density and structure of sp³ defects. A parametrized tight-binding model is then mapped onto the DFT results, thereby allowing for extending the calculations to much larger system sizes (up to 10⁶ atoms). We have next applied the real-space Kubo-Greenwood formalism to investigate the charge transport characteristics in graphene with various percentages of sp³ defects. The calculations show that although incomplete saturation of the sp³ defects density lines leads to the appearance of localized states within the otherwise band gap, those states do not participate in electron transport along the system, which remains effectively confined in the so-created quasi-one-dimensional semiconducting channels.