Novel synthesis approach for highly crystalline CrCl3/MoS2 van der Waals heterostructures unaffected by strain†

Controlling the layer-by-layer chemistry and structure of nanomaterials remains a crucial focus in nanoscience and nanoengineering. Specifically, the integration of atomically thin semiconductors with antiferromagnetic two-dimensional materials holds great promise for advancing research. In this work, we successfully demonstrate a new synthesis approach for high-crystallinity CrCl₃/MoS₂ van der Waals heterostructures via a thermodynamically optimized chemical vapor transport (CVT) process on c-sapphire (0001) substrates. The 2H-MoS₂ layers can be grown as monolayers or with varying twist angles whereas the deposition of CrCl₃ layers in a second step forms the well-defined heterostructure. Of particular significance are the sharp and clean edges and faces of the crystals, indicating high-quality interfaces in the heterostructures. Raman spectroscopy, AFM and HRTEM confirm the monocrystalline character and precise structure of these layered nanomaterials, in which their intrinsic properties are preserved and unaffected by strain. This can pave the way for next-generation applications, particularly in valleytronics, opto-spintronics, and quantum information processing.