Robust Ballistic Transport in Narrow Armchair-Edge Graphene Nanoribbons with Chemical Edge Disorder

A semiempirical model based on density functional results is used to study the effects of chemical edge disorder on the transport properties of armchair-edge graphene nanoribbons. Despite a strong scattering potential induced by substituting randomly F for H atoms along their edges, carriers injected close to the band gap in ribbons as narrow as 4.8 nm exhibit ballistic transport over hundreds of nanometers. The results indicate that robust ballistic transport can be maintained in the presence of chemical edge disorder so long as the terminating atoms and/or functional groups remain one-fold-coordinated to the edges and do not contribute states to the pi-network within several eV of the gap.