Characteristics of nanostructured Ag films by the reduction of sputtered AgO_x thin films

The fabrication process and the optical properties of nanostructured silver (Ag) films made from silver oxide (AgO_x) thin films have been studied in detail. The formation of Ag nanoparticles with a diameter of about 50 nm during the reduction of AgO_x films was clearly demonstrated by scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (TEM) observations. The reflectance spectra of the nanostructured Ag films exhibited an intensive localized surface plasmon resonance (LSPR). The transformation in the reflectance spectra with reduction time was in good agreement with computer simulations based on Mie theory. The composition ratio of AgO_x films during the reduction was analysed by the Ag L _III edge x-ray absorption near-edge structure (XANES) measurements.