Fabrication and Characterization of Hydrophilic TiO₂ Thin Films on Unheated Substrates Prepared by Pulsed DC Reactive Magnetron Sputtering

Abstract

TiO2thin films were deposited on unheated silicon wafers (100) and glass slides by a pulsed DC reactive magnetron sputtering in an ultrahigh vacuum (UHV) system. The effects of both an operating pressure and deposition time on film structure, surface morphology, and optical property were studied. The film structure and microstructure were characterized by grazing-incidence X-ray diffraction (GIXRD) technique and transmission electron microscopy (TEM). The surface morphology was investigated by field emission scanning electron microscopy (FE-SEM). The optical property of theTiO2thin films was determined by spectroscopic ellipsometry (SE). The water contact angle measurement was also used to determine hydrophilicity of the films after exposed to UV light. The results suggested that theTiO2thin film at less than 40 nm was amorphous. As the thickness was increased, the mixture of anatase and rutile phases ofTiO2began to form. By reducing the operating pressure during the film deposition, the rutile phase component can also be enhanced. Both the increased film thickness and decrease operating pressure were the critical factors to improve the hydrophilicity of theTiO2thin films.

TiO2 nanotree films for the production of green H2 by solar water splitting: From microstructural and optical characteristics to the photocatalytic properties

“…Furthermore, the refractive index n and the extinction coefficient k reported in Fig. S6 (SI) using the Cody-Lorentz model are similar to previous SE spectra used to analyze amorphous and crystalline anatase [32,49,50]. We observed an increase in n with decreasing T d (Fig.…”

“…The electrical properties are investigated at the nanoscale by conductive atomic force microscopy (C-AFM) and at the macroscale by Hall effect measurements. We fit spectroscopic ellipsometry (SE) measurements using the Cody-Lorentz model [32], a powerful tool to determine the thickness, the band-gap, and the refractive index that is affected by the porosity. We correlate the outcome of this comprehensive microstructural, electrical, electronic, and optical study with the photocatalytic activity measured by two techniques.…”

Photocatalytic activity of thin TiO2 films deposited using sol–gel and plasma enhanced chemical vapor deposition methods

“…Photogenerated properties also include the superhydrophilic effect, consisting in a substantial lowering of water contact angle under the exposure to UV radiation. Transparent superhydrophilic TiO 2 films deposited onto glass substrates may be used in such practical applications as antifogging and self-cleaning surfaces [9][10][11].…”

“…Among stable polymorphic forms of TiO 2 , anatase appears to have the strongest potential for photoinduction, while rutile is thought to be less effective [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The amorphous phase, on the other hand, was long considered incapable of inducing the photocatalytic effect and consequently of obliterating microorganisms and oxidizing organic and inorganic compounds.…”

“…TiO 2 coatings can be prepared by a number of deposition techniques, such as the sol-gel process [3,[16][17][18][19], reactive sputtering [10,13], chemical vapor deposition [20], spray pyrolysis [21], or plasma enhanced chemical vapor deposition (PECVD) [22][23][24]. Due to its simplicity and low costs, the sol-gel method is the most popular.…”