HUMIDITY-SENSITIVE PROPERTIES OF TITANIA FILMS PREPARED USING THE SOL-GEL PROCESS

TiO2 films, as well as powders as reference, were prepared using the s ol-gel process, using titanium isopropylalkoxide (TIPT) as a precursor . The films were deposited on glass slides and heated either to 300-de grees-C or to 500-degrees-C. The morphology of the film surface was ob served using scanning electron microscopy (SEM). Fourier transform inf rared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectro n spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) at different relative humidities were carried out to study the possib ility of using sol-gel processed titania films as detecting elements i n humidity sensors. A good resistance versus relative humidity (rh) se nsitivity was observed in the range from 50% to 85% rh. The response t ime of titania films was rather fast, estimated in a few seconds.