Electronic band structures and spin-charge densities of edge-functionalized silicene nanoribbons as promising candidates for either optoelectronics or spintronics applications

Abstract

Two-dimensional nanomaterials including graphene as well as its nanoribbons have started to occur, which has accelerated the growth of contemporary nanotechnology. Silicene, a silicon equivalent of graphene, has the main advantage that it can be employed in present silicon nanostructure-based production processes. Using density functional theory within the generalized gradient approximation, we offer the structural, electronic, and magnetic properties of edge-functionalized silicene nanoribbons (nX-zSiNR-mX’)(where, X/X’ = F, Cl or H; n, m = 1 or 2) in magnetic-order NM, FM, and AFM, respectively. Two modes homogeneous and heterogeneous asymmetric are accomplished. The spin density is mainly localized on halogen and Si atoms. Thus, future spin-dynamics processes for spintronics applications could be accomplished on these systems. Our computed outcomes reveal that the pristine nanoribbon 8-SiNR is a metal material once the NM and FM magnetic orders are involved, whereas it is a semiconductor with a small band gap energy when the AFM magnetic order is employed. Moreover, we find that the zigzag nX-zSiNR-mX’ compounds are metals in either case homogeneous or even heterogeneous. Nevertheless, a band gap energy up a limit to 520 meV (2H-zSiNR-1H) can be achieved under an external electric field with a strength of 4.0 V/Å. We carefully investigate the effect of the edge-functionalized silicene nanoribbon width on their spin density distribution and electronic band structures. Further, the effect of nanoribbon width on the edge formation energy and magnetic moment is systematically studied. Our outcomes reveal the potential of these nanoribbons as advantageous candidates for silicon photonic, optoelectronic devices, and spintronics applications.