Spin-filtering and rectifying effects for Al-doped zigzag-edged silicene nanoribbons with asymmetric edge hydrogenation

Abstract

Spin transport features of the Al-doping zigzag-edged silicene nanoribbons (ZSiNRs) are investigated by using the nonequilibrium Green's function method and the spin-polarized density functional theory, where ZSiNRs are Si–H2 bonded at one edge while Si–H bonded at the other to form an asymmetric edge hydrogenation. It is found that a perfect spin filtering effect (100%) in such ZSiNRs can be achieved in the calculated bias region. The rectifying performance of spin-polarized currents with a ratio larger than 105 can be achieved by changing the position of the doping atoms. Moreover, the negative differential resistance (NDR) effect is also observed in the spin-polarized current. Our calculation suggests Al-doping ZSiNRs with the asymmetric edge hydrogenation hold promise for multifunctional spintronic devices.