Optical studies of Au@SnO 2 /poly-(vinyl) alcohol core-shell nanoparticle thin films

Au@SnO 2 core-shell nanoparticles dispersed in poly-(vinyl) alcohol films were fabricated on glass substrate by employing dip-coating technique. The structure and morphology of the films were investigated by X-ray diffraction technique and field-emission transmission electron microscopy, respectively. Optical properties of the films were studied by UV–visible spectroscopy. Surface plasmon spectrum of the core-shell nanoparticles film remained unaltered with increase in the number of layers. However, gold nanoparticles films have shown peak broadening and shifting with increase in the number of layers. Our investigations showed that the surface plasmon band of the gold nanoparticles could be tailored and preserved by controlled deposition of tin dioxide shell.