▎ 摘　　要

In this paper the effect of normal compressive strain on the electronic and mechanical properties of multilayer molybdenum disulfide (MoS2) and graphene/MoS2 heterostructure are examine using density functional theory. The effects of layer number and stacking order of layers on the band structure and elastic constants are studied. Two different graphene/MoS2 heterostructure were studied. The first heterostructure consists of 5 x 5 graphene and 4 x 4 MoS2 unitcells in which MoS2 is compressed, whereas the second one is constructed of 4 x 4 graphene and 3 x 3 MoS2 unitcells and MoS2 is stretched in this structure. We find that due to sensitive dependence of the band gap of multilayer MoS2 on the normal compressive strain, a semiconductor-metal transition can be observed. The elastic constant of multilayer MoS2 increases with the rise in the number of layers, while the band gap decreases. Our simulations also illustrate that the AA(3) and AB(3) stacking orders are the most unstable structures. In the first heterostructure, the Schottky barrier strongly depends on the normal compressive strain. The n-type to p-type Schottky barrier transition occurs at the strain of 13.5%. In addition normal compressive strain changes the charge transfer between graphene and MoS2 in the second heterostructure. Furthermore, the direct and indirect band gap of MoS2 in the heterostructures can be adjusted by normal compressive strain and owning to stretching of MoS2, the band gap of MoS2 is smaller in the second heterostructure.