Tuning the electronic and quantum transport properties of nitrogenated holey graphene nanoribbons†
Recently, a new semiconductor two-dimensional (2D) material, namely, holey nitrogenated graphene 2D crystal (C2N-h2D), has been fabricated by using a bottom-up wet-chemical reaction. Using first-principles density functional theory (DFT) combined with the non-equilibrium Green's function (NEGF) technique, we investigate the atomic, electronic and quantum transport properties of porous C2N nanoribbons having both zigzag- and armchair-terminated edges. The zigzag C2N-h nanoribbons (ZC2N-hNRs) are semiconductors with an indirect band gap that decreases as the ribbon width increases. Meanwhile, the armchair C2N-h nanoribbons (AC2N-hNRs) show a metallic behavior for all ribbon widths, except for one of the candidates considered in this study, which presents a small band gap (0.14 eV). Interestingly, non-equilibrium calculations suggest that these structures display edge-dependent electronic transport properties where the armchair C2N-hNRs show a strong negative differential resistance (NDR) behavior with current peak-to-valley ratios that remarkably increase with increasing ribbon width, and non-linear current–voltage characteristics were found for the zigzag C2N-hNRs.