Novel half-metal and spin gapless semiconductor properties in N-doped silicene nanoribbons

We carry out a spin polarized first-principles study on the energetic and electronic properties of zigzag silicene nanoribbons (ZSiNRs) doped with N atoms, as well as N and Si vacancy (VSi) complexes. The formation energy analysis shows that the doped N atom and N-VSi complex prefer the edge sites in ZSiNRs. Due to breaking the degeneracy of the spin-polarization in ZSiNR, the substitution of N for Si atom exhibits a spin gapless semiconductor (SGS) property. When the N-VSi complex is introduced forming so called pyridine- and pyrrole-like structure in ZSiNR, they also exhibit half-metal or SGS behaviors with 100% spin-polarized currents in the Fermi level. These interesting properties may further stimulate potential applications of silicene-based nanostructures in nanoelectronics.