Effects of electric field on the electronic structures of MoS2/arsenene van der Waals heterostructure

Electronic structures modulation in MoS2/arsenene van der Waals (vdW) heterostructure with an external electric field (Eext) are investigated by density functional theory (DFT). It is demonstrated that the MoS2/arsenene heterobilayer is a type-II vdW heterostructure, and therefore electrons and holes are spatially separated. The band gap of MoS2/arsenene is significantly modulated by Eext, eventually a transition from semiconductor to metal occurs. The positive and negative Eext have different effects on the band gap due to the spontaneous electric polarization in MoS2/arsenene heterostructure. The variation of band edges as a function of Eext provides further insight to the linear variation of the band gap. Furthermore, the MoS2/arsenene vdW heterostructure experiences transitions from type-II to type-I and then to type-II under various external electric fields. The Eext can control not only the amount of charge transfer but also the direction of charge transfer at the MoS2/arsenene interface. The present study would open a new avenue for application of ultrathin MoS2/arsenene heterojuction in future nano- and optoelectronics.