Theoretical investigation on electronic and optical properties of the graphene-MoSe2-graphene sandwich heterostructure

We theoretically investigated the structural stability, electronic and optical properties of the sandwich graphene-MoSe 2 -graphene (G-MoSe 2 -G) heterostructure via the density functional theory (DFT). The simulation revealed that the relative movement of the layers along the plane can hardly affect the electronic and optical properties, as well as the structural stability. However, both the vertical and biaxial strain applied to the sandwich heterostructure can significantly modify the band structure, which results in the change of electronic and optical properties. We elucidated the mechanism for the band tuning by examining the projected band structure and the charge transfer between graphene and MoSe 2 layers. In the meantime, the absorption peak at ∼ 1.3 μm shifted with the increase of the strain. We believe that the sandwich heterostructure can be of great interest for applications as optical modulators, sensors and photodetectors.