On the fabrication and characterization of graded slanted chiral nano-sculptured silver thin films

Graded slanted chiral sculptured silver thin films are produced using oblique angle deposition together with rotation of substrate holder about its surface normal, plus a shadowing block, fixed at the center of the substrate holder. Scanning electron microscope (SEM) and atomic force microscope (AFM) were used for characterization of these films. The results showed a structural gradient with distance from the edge of the shadowing block, which in turn is responsible for the decrease in the volume of void fraction and increase of grain size. Plasmon absorption peaks observed in the optical analysis of these nano-structures showed that their wavelength region and intensity depend on the polarization and the incident angle of light, as well as the distance from the edge of the shadowing block. Photoluminescence (PL) study of the samples showed that there is an inverse size dependence of the PL spectra intensity.