Tuning from Half-Metallic to Semiconducting Behavior in SiC Nanoribbons

Half-metallic nanoscale conductors, highly sought after for spintronic applications, are usually realized through metal elements, chemical doping, or external electric fields. By means of local and hybrid density functional theory calculations, we identify pristine zigzag silicon carbide nanoribbons (zSiC-NRs) with bare edges as a metal-free monolayered material that exhibits intrinsic half-metallic behavior without chemical doping or an external electric field. Ab initio molecular dynamics simulations indicate that the half-metallicity is robust at room temperature. We also demonstrate that edge termination with O and S atoms transforms the zSiC-NRs into a full metal or a semiconducting material, respectively, due to the presence of O dimerization only on the Si edge and of S trimerization on both Si and C edges, the latter being driven by an unusual Peierls-like distortion along the functionalizing S atoms. The rich electronic properties displayed by zSiC-NRs may open new perspectives for spintronic applications using layered, metal-free, and light atom material.