Electronic structures of zigzag silicene nanoribbons with asymmetric sp2−sp3 edges

Abstract

The nanomaterials with peculiar spintronic characteristics, such as half-metals, spin gapless semiconductors [X. L. Wang, Phys. Rev. Lett. 100, 156404 (2008)], and bipolar magnetic semiconductors [Li et al., Nanoscale 4, 5680 (2012)], play the crucial role in nano-electronics and spintronics. Here, we report the zigzag silicene nanoribbons (ZSiNRs) with asymmetric sp2−sp3 edges are bipolar magnetic semiconductors due to the incorporation of Klein and zigzag edge states. With the bipolar feature, these asymmetric ZSiNRs can be altered to half-metals with opposite conductive spin channels by p-type and n-type dopings. Moreover, the semiconducting properties can also be tailored by the strain, which makes the nanoribbons into spin gapless semiconductors or ferromagnetic metals.

Magnetic properties of silicene nanoribbons: A DFT study

“…This can be done easily by saturating the bare edge with one H atom to form the H2-ZSiNR-H model. 35 After the original dangling sp 2 -σ orbitals at bare edge are saturated, it is far away from E F , leaving pz-π to be the only edge states. The calculated total energies (PM: -86.121eV, FM: -86.199eV, FI: -86.189eV) shows that the FM state is 10.23meV lower than that of the FI state.…”

Antiferromagnetic half-metals, gapless half-metals, and spin gapless semiconductors: The D03-type Heusler alloys

“…Not only the excited electrons but also the holes can be completely spin-polarized, which results in unique transport properties: the coexistence of high resistance and high Curie temperature. In recent several years, SGSs have been theoretically predicted in Co-doped PbPdO 2 , 10 N-doped zigzag grapheme nanoribbons, 11 zigzag silicone nanoribbons with asymmetric sp 2 -sp 3 edges, 12 and several ternary and quaternary Heusler compounds. [13][14][15] Among them, Mn 2 CoAl (Ref.…”

Transport properties of bare and hydrogenated zigzag silicene nanoribbons: Negative differential resistances and perfect spin-filtering effects

“…For example, the ZSiNRs with asymmetric sp 2 -sp 3 edges are bipolar magnetic semiconductors, resulting from the incorporation of Klein and zigzag edge states, and they can be tuned to the half-metallic state by p-type and n-type dopings. 10 Under a transverse field, the N-or P-doped monohydrogenated ZSiNRs can be transformed from a magnetic semiconductor to a half metal. 11 Using first-principles calculations, Luan et al studied the electronic and magnetic properties of ZSiNRs and ASiNRs doped by the B-N bonded pairs, and they found a marvelous spin gapless semiconductor character with 100% spin polarization at the Fermi level when the B-N bonded pair was doped at the edge or subedge sites.…”