Linear giant Stark effect in WSe2 nanoribbons

In this paper the electronic properties of WSe2 nanoribbons is theoretically and numerically investigated by using six-band tight-binding (TB) model. Zigzag and armchair models of WSe2 nanoribbon show semiconducting and metallic phases, respectively. Effect of external electric field on the electronic properties of WSe2 via solving the Laplace's equation is also studied. A semiconductor-metal phase transition is observed for armchair structure by 2.1Vw of applied transverse electric field, where w is the width of the ribbon. A linear giant Stark effect is also occurred in both armchair and zigzag WSe2 nanoribbons by variations of applied transverse electric field. Moreover, we investigate electronic transport of armchair WSe2 nanoribbon putting on a ferromagnetic EuS substrate using nonequilibrium Green's function method. Spin polarization is occurred by effect of an exchange field of 0.2eV, induced by a ferromagnetic EuS substrate.