A first-principles study on the electronic transport properties of symmetric B/N co-doped armchair graphene nanoribbons with H/O co-saturation

Tuning the transport properties of graphene-based devices to achieve better performance is a fascinating but tough challenge. To overcome this challenge, we created one-dimensional nanostructures that resemble chains by symmetrically doping B and N atoms at different positions in armchair graphene nanoribbons (AGNRs) of different widths saturated by H/O atoms. Their transport properties, including band structure, the spatial dis-tribution of eigenstates, the projected density of states (PDOS), and current-voltage (I-V) curve, have been investigated depending on the non-equilibrium Green's function (NEGF) and Density functional theory (DFT) methods. Based on the calculations, the seven-atom-wide armchair graphene nanoribbons (7-AGNRs) have a distinctive negative differential resistance (NDR) effect with a maximum peak-to-valley ratio (PVR) of 3.34 x 106. We speculate that the NDR effect depends on the strength of the coupling between the band structures of the electrodes within the transmission window, and that the degree of overlap between the Pz orbitals of the doped atoms and their delocalized big & pi; orbitals is also relevant. Compared to the existing diodes with fully hydro-genated or fluorinated edges, diodes with H/O co-saturated edges have lower start-up voltages and higher currents in the doped case, as well as rectification ratio of up to 4.48 x 106 in the range of [1.1 V, 1.4 V]. Our results have great promise for applications in digital and storage devices as well as in novel oscillators and nanoelectronics.

Automated summary

We created one-dimensional nanostructures resembling chains by doping B and N atoms at different positions in armchair graphene nanoribbons (AGNRs) of different widths saturated by H/O atoms. The transport properties of these structures were investigated using non-equilibrium Green's function (NEGF) and Density functional theory (DFT) methods. Based on calculations, the 7-atom-wide armchair graphene nanoribbons (7-AGNRs) exhibited a distinctive negative differential resistance (NDR) effect with a maximum peak-to-valley ratio (PVR) of 3.34 x 106. Diodes with H/O co-saturated edges showed lower start-up voltages, higher currents, and rectification ratios of up to 4.48 x 106 in the doped case compared to existing diodes with fully hydrogenated or fluorinated edges. These results have significant potential for applications in digital and storage devices, as well as novel oscillators and nanoelectronics.