First-Principles Study of the Graphene@MoSe2 Heterobilayers

Very recently, the graphene@MoSe 2 heterobilayers [G@MS HBLs] were successfully synthesized experimentally. In this work, the adhesion and electronic properties of the G@MS HBLs have been studied by using density functional theory. It is found that the graphene is weakly bound to the MoSe 2 monolayer without any site selectivity. The bands of G@MS HBLs have characteristic graphene-like features with a small band gap (2 meV) opening at K. However, the gap value is significantly lower than k B T at room temperature and can even vanish at room temperature, which suggests that the unusual electronic properties of graphene in G@MS HBLs are comparable to those in the free-standing graphene. Thus, the MoSe 2 monolayer might be considered as a promising substrate for potential graphene-based devices. The physical origin of the semiconducting property is related to the inhomogeneity of the onsite energy of C atoms induced by MoSe 2 . Our results provide a detailed understanding of the interfacial properties of G@MS HBLs and help to predict the performance of graphene-based nanoelectronics and nanocomposites.