| AVS 65th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Film Poster Session |
| Presenter: | Akihiro Joichi, Kogakuin University, Japan |
| Authors: | A. Joichi, Kogakuin University, Japan I. Takano, Kogakuin University, Japan |
| Correspondent: | Click to Email |
In recent years, various properties of TiO2 have attracted attention and the studies have been conducted in a wide field. Particularly, in photocatalytic properties, TiO2 have antifouling or antibacterial actions, and is applied to the outer wall of the building or the inner wall of the operating room. However, as the inferior point of TiO2, the absorption wavelength is limited to an ultraviolet light. In the previous study, it was attempted to expand the absorption wavelength to a long wavelength by inserting a Cu2O layer under a TiO2 layer. On the other hand, because the photocatalytic properties of TiO2 deteriorated by Cu diffusion from Cu2O, a NiO layer or a TaON layer was inserted as the intermediate layer to prevent the diffusion. In this research, the effect of an inserted ZnO layer was investigated for the photocatalytic property and was compared with a NiO layer or a TaON layer.
Glass (Eagle XG) plates processed to 15 mm × 9 mm were used as substrates, and ultrasonic cleaning was performed using acetone for 5 minutes for the substrates. The multi-process coating apparatus (BC5146, ULVAC) was used to clean up the substrate by rf sputtering and to deposit the thin films of TiO2, ZnO and Cu2O. The deposition chamber was equipped with RF and DC sputtering cathodes. Each oxide film was formed by sputtering a Ti, a Cu or a Zn metal target in an O2 atmosphere. The ultimate pressure of the deposition chamber was 8.0 × 10 -6 Pa and deposition pressure was 0.08 Pa by introducing an Ar and an O2 gas. Photocatalytic properties were measured by a methylene blue immersion test. In the methylene blue immersion test, a quartz cell filled by 3 ml of a methylene blue solution of 10 ppm was used and the sample immersed therein was irradiated by sterilizing light or artificial sun light for 6 hours. The chromaticity change of the methylene blue solution was measured by using a spectrophotometer at a predetermined time.
In the multi-layer thin films inserting different oxide layers, the photocatalytic measurement of the TiO2/TaON/Cu2O thin film showed the highest transmittance, because the optimum condition of a ZnO layer was not enough. The optimum thickness of a ZnO layer will be investigated until the conference.