Enhanced Carrier Concentration and Electronic Transport by Inserting Graphene into van der Waals Heterostructures of Transition-Metal Dichalcogenides

We live in an age of designer materials, where device structure and material heterostructure become one. For example, inserting graphene into a van der Waals multilayer may open opportunities to design high-performance nanodevices. This theoretical study of the electronic structures and properties of MoS${}_{2}$/graphene/W${X}_{2}$ ($X$ = S, Se) heterostructures reveal their high thermal stability, staggered band alignments, and intact Dirac cones. In particular, the transport current in systems with graphene is two orders of magnitude higher than in those without. These results point the way to designing high-performance optoelectronic devices based on two-dimensional semiconductors.