Moiré patterns in graphene-rhenium disulfide vertical heterostructures

Vertical stacking of atomically thin materials offers a large platform for realizing novel properties enabled by proximity effects and moiré patterns. Here, we focus on mechanically assembled heterostructures of graphene and ReS2, a van der Waals layered semiconductor. Using scanning tunneling microscopy and spectroscopy, we image the sharp edge between the two materials as well as areas of overlap. Locally resolved topographic images revealed the presence of a striped superpattern originating in the interlayer interactions between graphene's hexagonal structure and the triclinic, low in-plane symmetry of ReS2. We compare the results with a theoretical model that estimates the shape and angle dependence of the moiré pattern between graphene and ReS2. These results shed light on the complex interface phenomena between van der Waals materials with different lattice symmetries.