Carrier Transport in Armchair and Zigzag Graphene Nanoribbons

The conductivity of armchair and zigzag graphene nanoribbons in the presence of Coulomb scattering due to the charged impurities is investigated theoretically based on the Boltzmann transport equation formalism. The influence of different relevant physical parameters on the conductivity is examined. It is found that the combined effects of Fermi energy, impurity density, distance between impurity carriers, and width of the graphene strips are all able to modify the conductivity of graphene nanoribbons. The conductivity show an increasing trend by increase of Fermi energy and width, which is assigned to the increase of the occupied sub-bands number. Our numerical results predict that the conductivity of zigzag and armchair nanoribbons are qualitatively similar.