▎ 摘　　要

Inserting graphene into van der Waals (vdW) heterostructures (HTSs) may result in unprecedented opportunities to design high-performance nanodevices, although the underlying physical mechanisms are unclear. Here, we present theoretical studies on electronic structures, carrier concentrations, and electronic transport of the MoS2/graphene/WX2 (X = S, Se) vdW HTSs. The studies show that the MoS2/graphene/WX2 sandwiched systems have the desired characteristics of highly thermal stability to at least 500 K, staggered band alignments, and intact Dirac cone. In particular, the transport currents of the MoS2/graphene/WX2 HTS are two orders of magnitude higher than that of the MoS2/WX2 HTS, which indicates that the insertion of graphene obviously enhances the transport properties. Moreover, the external electric field can induce p-type doping of graphene and remarkably enhance the carrier concentration from approximately 10(11) to approximately 10(13) cm(-2). The results reveal the physical nature of MoS2/graphene/WX2 vdW HTSs, which are helpful in providing a route to design two-dimensional semiconductor-based high-performance optoelectronic devices.