Preparation of Au/SiO2 nano-composite multilayers by helicon plasma sputtering and their optical properties

Abstract

Au/SiO2 nano-composite multilayers were prepared by helicon plasma sputtering. The Au particles dispersed in the SiO2 matrix grew with increasing deposition time in the initial time less than 10 s, then changed from network-like to film-like microstructure with increasing deposition time. The optimum deposition time for preparing the Au particles was 8 s, and the size of Au particles was about 6 to 8 nm. The absorption peak due to the surface plasmon resonance of Au particles was observed at the wavelength of 560 nm in the optical absorption spectra for the as-deposited Au/SiO2 thin films containing 3.3 to 10.3 vol%Au. The intensity of the absorption peak increased with increasing Au content, and the optimum Au content was about 10.3 vol%.