Theoretical investigation of the scaling behavior of doped edge states in zigzag graphene nanoribbons

Spin-polarized edge states of zigzag graphene nanoribbons (ZGNRs), specially those modified by doping, offer potential for spintronic applications. This work employs density functional theory to investigate the effects of nitrogen (N) and boron (B) doping on the electronic and spin properties of ZGNRs, with a particular focus on how these properties vary with ribbon width. Our results suggest that N-n-ZGNRs exhibit similar structural stability across a range of widths, whereas B-n-ZGNRs are more sensitive to width changes, leading to increased formation energies and lattice distortions. In N-n- ZGNRs, spin polarization remains robust and extends along the ribbon edges, whereas in B-n-ZGNRs, spin localization is confined to the vicinity of the dopant atoms. Furthermore, N-doping induces a more significant reduction in the energy gap as the ribbon width increases than B-doping does. These findings provide some insights into the tunability of the electronic and spin properties of ZGNRs through selective doping, which is highly important for the development of spintronic and nanoelectronic devices.