The electronic structure and transport properties of monolayer ${\mathrm{MoS}}_2$ are studied using a tight-binding approach coupled with the nonequilibrium Green's function method. A zigzag nanoribbon of ${\mathrm{MoS}}_2$ is conducting due to the intersection of the edge states with the Fermi level that is located within the bulk gap. We show that applying a transverse electric field results in the disappearance of this intersection and turns the material into a semiconductor. By increasing the electric field the band gap undergoes a two stage linear increase after which it decreases and ultimately closes. It is shown that in the presence of a uniform exchange field, this electric field tuning of the gap can be exploited to open low energy domains where only one of the spin states contributes to the electronic conductance. This introduces possibilities in designing spin filters for spintronic applications.

• Received 28 September 2016
• Revised 1 December 2016

DOI:https://doi.org/10.1103/PhysRevB.94.235424