Transparent, Homogeneous Tin Oxide (SnO2) Thin Films Containing SnO2-Coated Gold Nanoparticles

A sol–gel-based approach to the fabrication of tin oxide (SnO 2 ) thin films containing SnO 2 -coated gold nanoparticles is described. In this approach, gold nanoparticles with a mean diameter of ∼15 nm were coated with thin layers of SnO 2 . The composite particles were ∼55 nm in diameter with SnO 2 shells that were ∼20 nm thick. These nanoparticles were doped homogeneously into a SnO 2 sol–gel precursor, and the mixture was deposited as a thin film via spin-coating methods. The SnO 2 -coated nanoparticles and the SnO 2 films doped with the nanoparticles were characterized by transmission and scanning electron microscopy (TEM and SEM) and X-ray diffraction (XRD). The optical properties of the nanoparticles and the composite films were evaluated by UV–vis spectroscopy.