AVS 54th International Symposium
    Thin Film Tuesday Sessions
       Session TF-TuP

Paper TF-TuP20
Nitrogen-dope Effect for Photofunctional Properties of Titanium Dioxide Films Prepared by Magnetron Sputtering

Tuesday, October 16, 2007, 6:00 pm, Room 4C

Session: Aspects of Thin Films Poster Session
Presenter: J. Hamaguchi, Kogakuin University, Japan
Authors: J. Hamaguchi, Kogakuin University, Japan
I. Takano, Kogakuin University, Japan
M. Sato, Kogakuin University, Japan
Correspondent: Click to Email

Titanium dioxide is anticipated as one of materials which are alternative for existing solar cell technology based on silicon. Silicon has a wide wavelength range including visible light, while titanium dioxide has a shorter wavelength range under ultraviolet light, according to each band gap. Hence, many researchers have studied about improvement of absorbance band in titanium dioxide, such as doping of nitrogen using plasma,1 doping of chromium using ion implantation,2 or dye sensitization of titanium dioxide. In this study, photofunctional properties of nitrogen-doped titanium dioxide were investigated about the films prepared by each method of ion implantation to titanium dioxide and reactive magnetron sputtering. In the former, nitrogen ion implantation was performed after preparing titanium dioxide by reactive magnetron sputtering. In the latter, nitrogen doping was performed during formation of titanium dioxide by reactive magnetron sputtering in nitrogen gas atmosphere. Composition and microstructure of these films were investigated by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. Chromatic change of methylene blue solution was applied to photocatalytic property. Light irradiation to titanium dioxide in a methylene blue solution was carried out using a commercial sterilizing lamp as ultraviolet light and a commercial fluorescent lamp as visible light. Transmittance of a methylene blue solution was measured by a spectro photometer. Furthermore, photocurrent between titanium dioxide and platinum electrode were measured in a potassium hydrogencarbonate solution using an unresisted ammeter. In the case of nitrogen doping during film formation, photofunctional property using a fluorescent lamp showed lower photocatalytic effect and photocurrent as compared with the case of a sterilization lamp. The higher photocatalytic effect and photocurrent using a sterilization lamp were obtained at N2 gas flow rate of 0.6 sccm and 0.4-0.5 sccm respectively, while both properties using a fluorescent lamp also showed the same behavior as a sterilization lamp.

1R.Asahi, et al.; Science, 293(2001)269.
2S.Anpo, et al.; Surface Science Society of Japan, 20(1999)60.