| Project/Area Number |
11555225
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
工業分析化学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SAWADA Tsuguo The University of Tokyo, Graduate School of Frontier Sciences, Professor, 大学院・新領域創成科学研究科, 教授 (90011105)
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| Co-Investigator(Kenkyū-buntansha) |
KATAYAMA Kenji The University of Tokyo, Graduate School of Frontier Sciences, Research Associate, 大学院・新領域創成科学研究科, 助手 (00313007)
YUI Hiroharu The University of Tokyo, Graduate School of Frontier Sciences, Research Associate, 大学院・新領域創成科学研究科, 助手 (20313017)
FUJINAMI Masanori The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 大学院・新領域創成科学研究科, 助教授 (50311436)
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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 |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2000: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1999: ¥10,300,000 (Direct Cost: ¥10,300,000)
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| Keywords | positron / nanospace / defects / electron momentum / defect-impurity complex / Doppler broadening / oxygen / silicon / 時間分解 / ポンプープローブ法 / 半導体表面 / 近接場光 / 格子欠陥 / 過渡反射格子 / ピコ秒 |
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| Research Abstract |
The aim of this research project is to develop the time-resolved scanning probe microscope (SPM) and to apply it to the surface of semiconductors. To achieve the picosecond time-resolved measurement, the combination of the pump-probe technique and SPM is required. In this project, fast thermalization process of carrier in Si has been investigated using a wavelength-selective transient reflecting grating method. Dynamics of photo-excited carriers in Si involves carrier-carrier scattering, carrier-lattice scattering, recombination, diffusion, and trap into defect energy level. By analyzing wavelengh dependency in the transient reflecting grating response, it has been found that the relaxation process in several picosecond is attributed to change in dielectric constant at the Si surface and that one in 200 picosecond to thermally process induced by photo-excited carriers. This information is very useful to investigate fast phenomena of photo-excited carriers at the Si surface.
To combine the pump-probe methods with SPM, scanning near-field optical microscope (SNOM) with the fiber probe was chosen. We have realized the measurement of photothermal effect in SNOM configuration. The introduction of pump laser to the sample was used the evanescent light from the fiber probe. And then the absorption of light induced the change of refractive index, or the thermal lens, which was detected by deflection of probe laser. In this work, the dye molecules were excited by 532nm pump laser emitted from the fiber probe, and the thermal lens induced were detected by the 633nm probe laser transmitted from the fiber one. This is the first time to detect the thermal lens by evanescent excitation in SNOM configuration. We have a plan to develop the picosecond time-resolved SNOM to detect the photothremal phenomena by introducing the pulse laser to the fiber probe and to apply it to the surface in semiconductors.
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