Tunable band gaps in silicene-MoS2 heterobilayers

The geometric and electronic properties of silicene paired with a MoS2 substrate are studied systematically by using density functional theory with van der Waals corrections. It is found that the nearly linear band dispersions can be preserved in the heterobilayers due to the weak interface interactions. Meanwhile, the band gap is opened because of the sublattice symmetry broken by the intrinsic interface dipole. Moreover, the band gap values could be effectively modulated under an external electric field. Therefore, a way is paved for silicene-MoS2 heterobilayers to be candidate materials for logic circuits and photonic devices.