Electron Transport Modeling for Junctions of Zigzag and Armchair Graphene Nanoribbons (GNRs)

Conductance of a seamless string of zigzag/armchair/zigzag graphene nanoribbons (GNRs) is modeled using nonequilibrium Green's function methodology as a function of width, Fermi level and the metallic or semiconducting nature of the armchair GNR. Such a structure with a semiconductor armchair GNR combined with a top gate can potentially form a transistor whereas a structure with a metallic armchair GNR can be used for interconnecting nearby transistors. It is shown that the bends in such structures can be quite transparent for electrons (80% to 90% of ideal conductance) so long as there is the same number of conduction channels in the zigzag and armchair GNRs.