| AVS 55th International Symposium & Exhibition | |
| Energy Science and Technology Focus Topic | Tuesday Sessions |
| Session EN-TuP |
| Session: | Energy Focus Topic Poster Session |
| Presenter: | H.A. Shukur, Kogakuin Univeristy, Japan |
| Authors: | H.A. Shukur, Kogakuin Univeristy, Japan H. Nagai, Kogakuin University, Japan I. Takano, Kogakuin University, Japan M. Sato, Kogakuin University, Japan |
| Correspondent: | Click to Email |
Since TiO2 has been used as one of lower cost materials and is harmless to the environment, it is expected to use as a material of a clean energy system in future. Furthermore its photocatalysis have antifouling and antibacterial properties. At the same time, the electric property shows n-type semiconductor characteristics and is classified as a high dielectric material. However, details of electric property for TiO2 have not been researched on the relations between the oxygen deficit state and light. Generally the resistance of TiO2 is decreases by the excitation of electrons due to the light irradiation. We anticipate that these properties are applied to a photo sensor of electronic parts. In this study the electrical property of TiO2 thin film was investigated under irradiation with the ultraviolet or visible light. The formation conditions was changed the substrate temperature 100 and 200°C. Furthermore O2 flow rate was changed from 0.1 to 1.7 sccm for each substrate temperature. I-V property of films on a slide glass was measured by using an unresisted current meter under fluorescence light (FL), a black light (BL) or a sterilizing light (SL). The measurement size of the film was 200nm in thickness, 10 mm in length and 8 mm in width. The resistivity of films depends on O2 flow rate. On the other hand the films resistivities in both temperature conditions hadn’t a large different property until 1.3 sccm, but the films formed under substrate temperature 200°C showed a large resistvity. The microstructure of these films investigated by X-ray diffraction showed clearly that the both of O2 flow rate and substrate temperature affected films in crystalline structure. In case of high substrate temperature and large O2 flow rate, the crystalline structure of films changed to an anatase type and films resistivity was raised. The measurement of photoconduction current under each light irradiation showed two important results. Firstly the TiO2 thin films obtained a large effect of photoconduction current under BL irradiation in all formation conditions. The second point was that the photoconduction current reduced with increase of the film resitivity and the maximum photoconduction current was obtained at the film of 0.5 sccm with both of a substrate temperature.
1Akira Fujishima, Kazuhito Hashimoto and Toshiya Watanabe, “TiO2 Photocatalysis Fundamental and Applications”.