PHOTOINDUCED WETTABILITY OF TITANIUM OXIDE THIN FILMS

Abstract

We present here the results of a systematic investigation of the influence of the main deposition parameters (substrate temperature, deposition time, reactive gas composition, etc.) on the hydrophilic properties of DC sputtered titania films, grown on heated glass substrates (463-573 K), using water vapors as the reactive gas. Reference samples prepared in standard oxygen-based deposition conditions were used to compare the results. All the investigated samples were polycrystalline, with either pure anatase or mixed anatase-rutile nano-phase mixtures, depending on substrate temperature and film thickness. The surface wettability, evaluated from contact angle data during UV irradiation and in the back-reaction conditions, is discussed in terms of the synergic effects of materials structure, surface morphology, elemental composition, and electronic properties.