Growth of Au–TiO2 nanocomposite thin films by a dual-laser, dual-target system

Abstract

Nanocomposite thin films formed by gold nanoparticles embedded in a titanium dioxide matrix have been synthesized by pulsed laser deposition. Two synchronized laser sources, an ArF* excimer (λ=193nm, τFWHM∼12ns) laser and a frequency tripled Nd:yttrium aluminium garnet (λ=355nm, τFWHM∼10ns) laser, were used for the simultaneous ablation of the titanium dioxide and gold targets. The optical absorption characteristics of the obtained nanocomposites were investigated as a function of laser parameters used for the ablation of the gold target. The obtained results proved the possibility of tuning the optical properties of gold–titanium dioxide nanocomposites with the proper choice of laser irradiation parameters. Band gap narrowing and absorption in the visible spectral region induced by the incorporation of gold enable the design of nanostructured thin films to be achieved for photocatalysts and solar energy converters.