Abstract

SnO2 thin films with nanowhiskers (SnO2-tf-Nws) were prepared through Sn02 films thermal oxidation obtained by condensed vapors deposition (DCVM). Different amounts of metal moles (mem) were used, as well as different cooling times of the glass substrates, which were directly in contact with the reactor walls at –195 °C and two oxidation temperatures, at 500 °C and 600 °C for 8 hours. Structural and morphological characterization was performed by XRD, AFM and SEM. X-ray diffraction determined that SnO2-tf-Nws are constituted by the rutile tetragonal phase of the SnO2. The nanowhiskers growth and transmittance of the oxidized films depended on the oxidation temperature. Optical properties were also assessed and analyzed as a function of the temperature and the amount of metal evaporated moles. Besides, the SnO2-tf-Nws were tested as gas sensors in order to detect oxidising and reducing gases such as NO2 and CO, respectively. The sensors presented significant responses for both gases and for the NO2 test it was observed a good response to low operating temperatures.