Gold-Nanoparticle-Doped TiO2 Semiconductor Thin Films: Optical Characterization

A simple procedure for creating titania sol–gel‐based semiconductor thin films is described. Gold nanoparticles are doped homogeneously into the precursor mixture and the particles are homogeneously distributed in the resultant films when prepared using spin‐coating. The effects of particle loading and annealing temperature on the optical properties of the resultant films are characterized. Ellipsometry, X‐ray diffraction, atomic force microscopy, and surface plasmon spectroscopy are used to monitor the crystallization and porosity changes during film synthesis. High volume fractions of size‐ and shape‐controlled gold nanoparticles are successfully embedded inside TiO2 sol–gel thin films (see figure). Up to 8 % v/v doping is achieved through a better understanding of the chemical interactions between the NPs and the matrix. The optical properties of the nanocomposites are investigated.