Ab initio study of electronic properties of graphene/MoS2 heterostructure under biaxial deformations

The electronic properties of strained graphene/molybdenum disulfide (Gr/MoS2) heterostructure have been studied by using density functional theory. It is known that the linear band dispersion relation of graphene undergoes insignificant changes in the case of graphene adsorption on MoS2 monolayer, when the in-plane lattice symmetry is broken, resulting in formation of a small band gap of 2 meV. At the present study, the equilibrium optimized state, corresponding to the maximal 14 meV band gap offset at 4% biaxial compression and 3.28 Å interlayer spacing, was found. It is established that the strain, applying to the Gr/MoS2 interface along x,y - directions, leads to a change in the interlayer distance, which is crucial for the band gap value. Our results suggest that such xy-plane deformations can be considered as a tool for selectively controlling value of the band gap, and will be useful for the design of the materials with desirably induced properties.