Abstract :
Tungsten trioxide and titanium dioxide thin films were synthesised by pulsed laser deposition. We used for irradiations of oxide targets an UV
KrF* (l = 248 nm, tFWHM ffi 20 ns, n = 2 Hz) excimer laser source, at 2 J/cm2 incident fluence value. The experiments were performed in low
oxygen pressure. The (0 0 1) SiO2 substrates were heated during the thin film deposition process at temperature values within the 300–500 8C
range. The structure and crystalline status of the obtained oxide thin films were investigated by high resolution transmission electron microscopy.
Our analyses show that the films are composed by nanoparticles with average diameters from a few to a few tens of nm. Moreover, the films
deposited at substrate temperatures higher than 300 8C are crystalline. The tungsten trioxide films consist of a mixture of triclinic and monoclinic
phases, while the titanium dioxide films structure corresponds to the tetragonal anatase phase. The oxide films average transmittance in the visibleinfrared
spectral range is higher than 80%, which makes them suitable for sensor applications
