Improvement of photo‐functional properties of TiO 2 thin film coated by W surface layer

TiO 2 thin films with a W layer to improve photo‐functional properties were prepared using the reactive magnetron sputtering method. The W thin films at a thickness of 0.4 to 2.5 mm were coated onto the TiO 2 thin films using the same magnetron sputtering. The surface chemical state of the W‐coated TiO 2 thin films measured by X‐ray photoelectron spectroscopy showed W metal and/or W oxide on the TiO 2 thin film. A spectrophotometer was used to investigate UV‐Vis absorption of the W‐coated TiO 2 thin films which absorb energy of longer wavelength than the TiO 2 thin film without the W surface layer. Visible‐light photocatalysis of the W‐coated TiO 2 thin films was improved by four points in the sample with a W layer thickness of 1.7 nm, and photoconductivity was improved by four times under an artificial sun lamp. It is demonstrated that these improvements in the photo‐functional properties were achieved by a different cause. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(3): 45–52, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11409