The Optical Properties of Individual Silver Nanoparticles in Ag/Ag2O Composites Synthesized by Oxygen Plasma Treatment of Silver Thin Films

In this work, we present a more complete description of the optical properties of the silver nanoparticles formed in silver oxide thin films. Ag/Ag2O composites were synthesized by treating silver thin films manufactured by thermal evaporation method with oxygen plasma afterglow. The results showed that exposing silver thin films to oxygen plasma afterglow leads to a monocrystalline structure of silver oxide. Consequently, the relationship between the crystal size and the characteristics of the plasmon optical absorption peaks was studied. A slight degradation of plasmon peaks of the individual silver nanoparticles was observed. We suggested that this degradation might be due to the mutual interaction between the individual silver nanoparticles located near the Ag2O grain shell and the larger silver nanoparticles in neighboring grains. We found that the degree of degradation is related to the Ag2O grain size. On the other hand, the origin of each fluorescence peak in the Raman spectra of the prepared films was determined.