Femtosecond pulsed laser deposition of nanostructured ITO thin films

Indium tin oxide (ITO) films have been prepared by Pulsed Laser Deposition performed by using, as ablation source, a frequency doubled Nd/glass laser, with a pulse duration of 250 fs. The deposited films have been analysed by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray analysis and X-ray photoelectron spectroscopy. The films are stoichiometric, compact and show a rough surface, formed by the coalescence of a large number of nanoparticles. The nanoparticles are probably ejected directly from the target and are the main constituents of the films. The films electrical resistivity depends from the substrate temperature and its lower value, obtained at 500 degrees C, is 3.4 x 10(-6) Omega m. The variation of the electrical resistivity in the presence of nitrogen oxide is an indication on the possible application of these films as gas sensors.