| Project/Area Number |
18560313
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Shibaura Institute of Technology |
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Principal Investigator |
TAKAO Nagatomo Shibaura Institute of Technology, Faculty of Engineering, Professor (70052868)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,980,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥480,000)
Fiscal Year 2007: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | photocatalysis / oxide semiconductor films / visible light response / RF sputtering / strontium titanate / perovskite structure / transition metal oxide Semiconductors / indirect transition / 薄膜・量子構造 / 高周波スパッタ法 / 表面構造と光触媒活性 / 光活性種 / 結晶構造と光触媒活性 / 酸化物半導体 |
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| Research Abstract |
Titanium dioxide (TiO_2) is a well-known, efficient photocatalysts. Strontium titanate (SrTiO_3)is also one of interest photocatalysts. In present work, we studied the photocatalytic activity of SrTiO_3 films in visible light region. Strontium titanate films were grown on pyrex glass and fused quartz glass by a RF magnetron sputtering. The crystalline structure of SrTiO_3 films was investigated by using X-ray diffraction. Three peaks of (100) ,(110) and (200) faces for the SrTiO_3 films on the glass substrates were observed. SrTiO_3 films are polycrystalline with perovskite structure. The absorption coefficients(α) of SrTiO_3 films were calculated from the absorbance data as a function of photon energy. The optical band gap of SrTiO_3 films was estimated according to Tauc relation [αE(hυ)]^<1/2>-E(hυ)(E(hυ): photon energy). The indirect band gap can be evaluated by extrapolating the linear portions of the plots. The indirect optical band gap of undoped SrTiO_3 films is measured to be 3.2-3.3 eV, which is in good agreement with the reported value. RF-sputtered SrTiO_3 films did not decompose methylene blue dye under UV illumination. It is one of the reasons that it is difficult to control the composition ratio than that of TiO_2 as SrTiO_3 has, the perovskite structure. Although the optimization of the film preparation conditions for activating the photocatalytic reaction was insufficient, we couldn't achieve the initial purpose. The titanium oxide (TiO_2) films fabricated by RF sputtering showed strong photocatalytic reaction under UV illumination. It is reported that TiO_2 films prepared by RF sputtering have photocatalytic activity under the visible light without doping of cation and anion by controlling the substrate temperature precisely.
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