Pt/TiO2 nanocomposite films were prepared by sputtering and pulsed laser de
position (PLD). The Pt/Ti atomic ratios in the films deposited by the PLD w
ere smaller than those in the ablation targets and those in the films prepa
red by sputtering. At low Pt concentration, Pt is deposited as PtO2 in the
films prepared by sputtering, whereas metallic Pt is deposited in the films
prepared by PLD. The Pt nanoparticle size in the as-deposited Pt/TiO2 nano
composite films prepared by PLD was about 30 nm, which is quite large compa
red to the 1-2-nm size in the sputter-deposited films. Pt nanoparticles wer
e produced in the growth processes via surface diffusion, which can be refl
ected by the kinetic energy of the chemical species spread from the target.
It can be inferred from the optical measurements of heated Pt/TiO2 nanocom
posite films that new energy levels are produced in the band gap of TiO2 by
the homogeneous dispersion of Pt nanoparticles in the TiO2 matrix.