Electronic structure of the interface between Au and WSe2

Understanding the interface between metals and two-dimensional materials is critical for their application in electronics and for the development of metal-mediated exfoliation of large area monolayers. Studying the intricate interactions at the interface requires model systems that enable control of the roughness, purity, and crystallinity of the metal surface. Here, we use angle-resolved photoemission spectroscopy to investigate the layer-dependent electronic structure of WSe{2}~on template-stripped gold substrates fabricated using both silicon and mica templates, giving crystallographically disordered and Au(111) ordered surfaces, respectively, and contrast these findings with ab initio predictions. We observe strong hybridization around the Brillouin zone centre at Γ̄, indicating a covalent admixture in the gold-WSe{2}~interaction, and band shifts that suggest charge rearrangement at the Au(111) / WSe{2}~interface. Core-level spectroscopy shows a single chemical environment for the interfacial WSe{2}~layer on the template-stripped gold, distinct from the subsequent layers. These results reveal a mixture of van der Waals and covalent interactions, best described as a covalent-like quasi-bonding with intermediate interaction strength.