Tunable electronic structure and magnetic moment in C₂N nanoribbons with different edge functionalization atoms

First principles calculations based on density functional theory were carried out to study the electronic and magnetic properties of C₂N nanoribbons (C₂NNRs). The electronic structure could be modified by different methods using saturated or co-saturated H, O, and F on the edges, which can provide a new pathway at the nanoscale for fabricating 2D spintronic materials. It was found that the pristine armchair C₂NNR (A-C₂NNR) is a nonmagnetic semiconductor with a direct band gap, while the pristine zigzag C₂NNRs (Z-C₂NNRs) can show either magnetic semiconductor with an indirect band gap or magnetic metallic behavior depending on its ribbon widths. A-C₂NNRs with one type of atom (H, O or F) saturated on the edges are nonmagnetic, while H and O (F and O) co-saturated A-C₂NNRs show magnetic ground states. H and O (F and O) co-saturated Z-C₂NNRs share a larger magnetic moment compared to the case with H, O and F saturated on the edges. Furthermore, O-saturated Z-C₂NNR is a spin "gapless" semiconductor. Additionally, there is no need to spin flip in the process of electronic transition near the Fermi level. Therefore, C₂NNRs might have potential applications in photoelectronic and spinelectronic devices.