| Project/Area Number |
08650996
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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 |
無機工業化学
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| Research Institution | Shonan Institute of Technology, Faculty of Engineering |
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Principal Investigator |
FUJITSU Satoru Shonan Institute of Technology, Associate Prof., 工学部, 助教授 (20165400)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Piezoelectric / zinc oxide / photo conduction / surface reaction / 圧電体 / 光還元 / 電界 |
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| Research Abstract |
In the research work, the photo conduction phenomena have been measured for zinc oxide with transparency, crystal c-axis orientation and high resistivity formed by doping of Li_2O.The following results have been obtained, especially for the desorption and reduction of oxygen on the surface which controlled the photo conduction properties mainly.
1) The current acceleration by photo irradiation was observed at the two photo energy region (3.2 and 3.5 eV). From the measurement under the controlled atmosphere, it was confirmed that the former acceleration was due to the electron excitation between the band and the latter was due to the oxygen desorption (reduction) on the surface. The increase and decrease in the resistivity was observed with the switching of the irradiation of the light of 3.5 eV.While the increase in resistivity in dark was not observed in vacuum or nitrogen. The photo reduction and the re-oxidation rate were accelerated and the duplication property was stabilized in the
… More
high humid atmosphere. The effect of atmosphere under the irradiation of light of 3.2 eV was smaller than that of 3.5 eV.
2) The decrease in the resistivity by photo reduction wa depressed by the grinding the surface mechanically. This change was restored by heating the sample at 600ﾟC in air. The XPS measurement showed the coating by OH on the surface of the ground sample, which should restrict the oxygen desorption.
3) The photo excitation in the current under the constant bias along the c-axis was larger than that along the other direction and this excitation depended on the applied bias. The larger excitation was observed under the larger applied bias. Such dependence was not observed in the measurement for the bias applying on the other direction. Since the c-axis of zinc oxide is a piezoelectric polarizing direction, it has been judged that the binding condition of oxygen in the surface changed by piezoelectric lattice distortion with the electrical field.
From these results, it was confirmed that we could control the photo reduction process on the surface of piezoelectric zinc oxide by applying electrical field. Less
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