Tunable band gap of MoS2-SiC van der Waals heterostructures under normal strain and an external electric field

The structure and electronic properties of the MoS2/SiC van der Waals (vdW) heterostructures under an influence of normal strain and an external electric field have been investigated by the first-principles method. Our results reveal that the compressive strain has much influence on the band gap of the vdW heterostructures and the band gap monotonically increases from 0.955 to 1.343 eV. The results also imply that electrons are likely to transfer from MoS2 to SiC monolayer due to the deeper potential of SiC monolayer. Interestingly, by applying a vertical external electric field, the results present a parabola-like relationship between the band gap and the strength. As the E-field changes from -0.55 to +0.18 V/Å, the band gap first increases from zero to a maximum of about 1.76 eV and then decreases to zero. The significant variations of band gap are owing to different states of Mo, S, Si, and C atoms in conduction band and valence band. The predicted electric field tunable band gap of the MoS2/SiC vdW heterostructures is very promising for its potential use in nanodevices.