First-principles study of electronic transport properties of graphene nanoribbons with pentagon-heptagon (5-7) line defects

Abstract

ABSTRACTIn this study, we investigated the influence of line defects consisting of pentagon-heptagon (5-7) pairs on the electronic transport properties of zigzag-edged and armchair-edged graphene nanoribbons (GNRs). Using the first-principles density functional theory, we study their electronic properties. To investigate their current-voltage (I-V) characteristics at low bias voltage (∼ 1 meV), we use the nonequilibrium Green’s function method. As a result, we found that the conductance of the GNRs having a connected line defect between source and drain shows better performance than that of the ideal zigzag-edged GNRs (ZGNRs). A detailed investigation of the transmission spectra and the wave function around the Fermi level reveals that the line defects arranged along the transport direction work similar to an edge state of the ZGNRs and can be an additional conduction channel. Our results suggest that such a line defect can be effective for low-resistance GNR interconnects.