Controllable Graphene/MoS2 Heterointerfaces by Perpendicular Surface Functionalization

Surface chemistry and interface interactions profoundly influence the properties of two-dimensional (2D) materials and heterostructures. Therefore, developing methods to precisely control surfaces and interfaces is crucial for harnessing the properties and functions of 2D materials and heterostructures. Here, we developed a facile approach to tuning the interface distance and properties of graphene/MoS2 heterostructures (G/MoS2) by varying the functional groups attached to the surface of graphene bottom layer. We systematically investigated how different functionalized graphene bottom layers affect the interlayer distance, coupling between the interlayers, and optical properties of resulting G/MoS2 heterostructures. Our findings indicate that both the size and electron-withdrawing/donating properties of functional groups are pivotal in regulating charge transport properties, with size playing a particularly decisive role. Our approach demonstrates an efficient and flexible pathway to regulate the interlayer spacing and charge transport, highlighting the potential of engineering interface chemistry in optimizing properties of van der Waals heterostructures.