Improvement of Photo-functional Properties of TiO_2 Thin Film Coated by W Surface Layer

摘要

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 photo-electron 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 photo-catalysis 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.