  Sub-10 nm continuous metal films are promising candidates for flexible and
transparent nanophotonics and optoelectronics applications. In this Letter, we
demonstrate that monolayer MoS2 is a perspective adhesion layer for the
deposition of continuous conductive gold films with a thickness of only 3-4 nm.
Optical properties of continuous ultrathin gold films deposited on
two-dimensional MoS2 grown by chemical vapor deposition are investigated by
spectroscopic ellipsometry over a wide wavelength range (300-3300 nm). Results
show that optical losses in ultrathin films increase with decreasing thickness
due to the fine-grained structure and the presence of a small number of voids,
however, they exhibit metallic properties down to a thickness of 3-4 nm. The
atomic-scale MoS2 interfaces can be transferred to any substrate and thus open
up new opportunities for the creation of metasurfaces and a new type of van der
Waals heterostructures with atomically thin metal layers.
