Absolute control of chirality unnecessary for wide-narrow-wide graphene field effect transistor

In contrast with carbon nanotubes, graphene nanoribbons (GNRs) suffer from edge roughness that dilutes its chirality dependence, creating a single inverse power law curve relating energy-bandgap and width. Thus all narrow nanoribbons (>10nm) are semiconducting while all wide nanoribbons are metallic. Our model which combines well-benchmarked semi-empirical Extended Huckel Theory (EHT)based electronic structure with an atomistic theory for quantum transport to illustrate this dilution of chirality dependence not-predicted by simplified tight-binding theory with ideal GNRs, but observed in experiments.