We investigate the diffusive electron-transport properties of charge-doped
graphene ribbons and nanoribbons with imperfect edges. We consider different
regimes of edge scattering, ranging from wide graphene ribbons with (partially)
diffusive edge scattering to ribbons with large width variations and
nanoribbons with atomistic edge roughness. For the latter, we introduce an
approach based on pseudopotentials, allowing for an atomistic treatment of the
band structure and the scattering potential, on the self-consistent solution of
the Boltzmann transport equation within the relaxation-time approximation and
taking into account the edge-roughness properties and statistics. The resulting
resistivity depends strongly on the ribbon orientation, with zigzag (armchair)
ribbons showing the smallest (largest) resistivity and intermediate ribbon
orientations exhibiting intermediate resistivity values. The results also show
clear resistivity peaks, corresponding to peaks in the density of states due to
the confinement-induced subband quantization, except for armchair-edge ribbons
that show a very strong width dependence because of their claromatic behavior.
Furthermore, we identify a strong interplay between the relative position of
the two valleys of graphene along the transport direction, the correlation
profile of the atomistic edge roughness, and the chiral valley modes, leading
to a peculiar strongly suppressed resistivity regime, most pronounced for the
zigzag orientation.Comment: 13 pages, 7 figure
