Monolayer Behavior of NbS₂ in Natural van der Waals Heterostructures

Monolayer transition metal dichalcogenides (TMDs) constitute an important family of materials with many intriguing properties and applications. The ability to achieve large-size and high-quality monolayer TMDs is the key prerequisite toward a deep understanding and practical application of TMDs in electronics and optoelectronics. Here, on the basis of high-resolution angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we find a monolayer NbS₂-dominated Fermi-level feature in a misfit compound, which is a type of natural heterostructures. Considering the infrequency of the synthesis approach and electronic properties of the NbS₂ monolayer, our results cannot only provide direct insight into the electronic structure of van der Waals heterostructures (VDWHs) but also shed light on the way toward rationally investigating  the monolayer TMDs, which are hardly obtained and studied.