Influence of silver thickness on optical properties of metal island films fabricated by physical vapour deposition

In this paper we report studies on the influence of silver island films´ thickness on their optical and surface-enhanced Raman scattering properties. The semicontinuous silver films of thickness in range 3-10 nm were fabricated using electron beam physical vapour deposition and their optical properties were characterized using UV-Vis-NIR spectroscopy. The SERS enhancement properties of fabricated films were evaluated using p-mercaptoaniline as an testing analyte. It was found that with increasing thickness of the silver films their plasmon resonance becomes broader and its maximum shifts toward longer wavelengths. The largest SERS signal enhancement was observed for the 7 nm thick Ag films.