Surface-enhanced Raman scattering from Ag nanoparticles formed by visible laser irradiation of thermally annealed AgO_x thin films

摘要

Visible laser irradiation of AgO_x thin films forms Ag nanoparticles, which then results in surface-enhanced Raman scattering (SERS). The efficiency of this Ag nanoparticle formation strongly depends on the properties of the AgO_x thin films. Thermal annealing causes changes in physical properties such as deoxidization of the films and aggregation of Ag atoms in the films. In the present research, the effects of the changes induced by thermal annealing on SERS efficiency were examined. It was found that AgO_x thin films annealed at 300℃ for 5 min in a N_2 atmosphere were suitable for the formation of Ag nanoparticles effective for SERS, while films that were not annealed were not. From these results, it was deduced that the Ag aggregation resulting from thermal annealing in AgO_x thin films promotes the Ag nanoparticle formation.