Observations of Electron Emission sites on Alumina Surface by using a Photoelectron Emission Microscope
| Project/Area Number |
11650279
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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 |
電力工学・電気機器工学
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| Research Institution | Saitama University |
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Principal Investigator |
KOBAYASHI Shinichi Saitama University, Faculty of Engineering, Prof., 工学部, 教授 (40008876)
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| Co-Investigator(Kenkyū-buntansha) |
MAEYAMA Mitsuaki Saitama University, Faculty of Engineering, Prof., 工学部, 助教授 (00196875)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Photoelectron emission microscope / Alumina / Photoelectron emission / Band gap / Defects / カソードルミネセンス / 重水素ランプ |
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| Research Abstract |
Electron emission sites on alumina surfaces have been observed by a photoelectron emission microscope (PEEM). Surface flashover is an obstacle to minimize the size of electric power devices, since surface flashover voltage on an insulator surface is fairy lower than that of gap breakdown voltage of the same gap lemgth. Surface flashover is dominated by electron emission from triple junctions and subsequent electron emission from the insulator surface. Electron emission properties from insulator surface have not been clarified yet. In this project, photoelectron emissionsites excited by ultraviolet light were observed. Maximum energy of the irradiated ultraviolet light was about 11 eV, which is greater than the band gap of alumina.
Observations revealed that photoelectron emission sites on alumina surface were localized (diameter < few μm) and the emission took place not continuously, but intermittently. This electron emission schem is quite different from that from metals, since the electron emission site expands over the who ; e area where excitation light was irradiated and electrons are emitted continuously. Also revealed by the observations was that lower energy of excitation light that that of the band gap of alumina could excite phoelectreon emission. This result confirms that energy bands created by crystal defects are formed in the band gap.
Further experiments to explain these electron emission properties from an insulator surface should be performed, on the basis of charging property, elemental analysis at the localized sites, and electronic states.
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Report
(3 results)
Research Products
(16 results)
