Oxidation-free and ultra-smooth thin silver films grown on a copper seed layer

Silver (Ag) films have been the noble-metal choice in nanophotonics for different innovative applications including plasmonics, superlens, hyperlens, nanoantennas, optical switching, organic light emitting diodes, organic solar cells, and many other nanoelectronic devices [1,2]. It is known that Ag thin films deposited by physical vapor deposition consistently reveal a rough surface morphology with larger grain size making them unsuitable for desired nanoscale devices and electrical interfaces [3,4]. Moreover, this increases the minimum thickness required to achieve continuous Ag films (11 nm), which is a crucial factor for many devices as larger thicknesses imply stronger optical losses.