Research on High Efficiency Photocatalyst for Optoelectronic Devices

Research Project

Project/Area Number	18560041
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Applied optics/Quantum optical engineering
Research Institution	Kansai University
Principal Investigator	SAITOH Tadashi Kansai University, Faculty of Engineering Science, Professor (30388417)
Co-Investigator(Kenkyū-buntansha)	INADA Mitsuru Kansai University, Faculty of Engineering Science, Lecturer (00330407)
Project Period (FY)	2006 – 2007
Project Status	Completed (Fiscal Year 2007)
Budget Amount *help	¥2,900,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥300,000) Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	semiconductors / optical properties / photocatalyst / 半導体物性 / 物性実験 / 表面・界面物性
Research Abstract	The oxide of titanium or the tungsten films deposited using the arc plasma evaporation are characterized. We describe here mainly the results on tungsten oxide films. 1. The titanium oxide films deposited under the lower oxygen partial pressure conditions during the evaporation showed the contact angle of water being smaller. This is thought the hydrophilic surface was obtained even under the room light in the case of titanium oxide films formed under less oxygen pressure conditions which include many oxygen deficiencies. 2. In case of tungsten oxide, the contact angle of water does not depend on the oxygen partial pressure during evaporation. There is a possibility that the hydrophilic surface was obtained even under the room light irradiation. 3. As for the tungsten oxide films formed with the arc plasma evaporation, the X-ray diffraction patterns indicated that they are tungsten trioxide films of which the activity as a photocatalyst is the strongest in tungsten oxides. 4. We estimated the energy-band gap of the heat-treated tungsten-oxide films by measuring the absorbance spectra. The processing temperature dependence of the band-gap energy was small, ranging from 2.6 to 2.9eV. These values are in good agreement with the reported values of the energy-band gap of tungsten trioxide, 2.6〜2.8eV. This result also suggests that it is possible to form tungsten trioxide using the arc plasma evaporation. As described above, we conclude that it is possible to form the tungsten-trioxide films, which exhibit the most strong photocalytic reaction under the visible light irradiation, using the arc plasma evaporation.