| Project/Area Number |
04640340
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Osaka University |
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Principal Investigator |
NAKAYA Hiroyasu Osaka University, College of General Education Assistant Professor, 教養部, 助教授 (60116069)
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| Co-Investigator(Kenkyū-buntansha) |
KOBORI Hiromi Osaka University, College of General Education Reserch Assistant, 教養部, 助手 (90202069)
FUJII Ken-ichi Osaka University, College of General Education Reserch Assistant, 教養部, 助手 (10189988)
OHYAMA Tyuzi Osaka University, College of General Education Professor, 教養部, 教授 (40029715)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | germanium / electron-hole plasma / far-infrared / photoluminescence / cyclotron resonance / diffusion / 半導体 / 輸送現象 |
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| Research Abstract |
this project aims to investigate the expansion mechanism of high-density electron-hole plasma generated in a semiconductor. We performed experiments on the plasma in Ge and GaAs. Fast diffusion of excitons accompanying with expanding plasma was observed in far-infrared magneto-aborption measurement. The dirift belocity decreases in magnetic fields and the expasion of the plasma is suppressed by magnetic fields. On the other hand, the ecperimental set-up of optically detected far-infrared cyclotron tesonance which has a possibility to observe the electron-hole plasma was newly developed and the resonance signal was observed in GaAs. We observed photoluminescence in 0.4-mm-thick Ge sample. Surface recombination deduces the density of free excitons. Further, far-infrred absorption of excitons is obserbed in this sample. The assignment is confirmed by the dependence on far-infrafed wavelength. The experimental results of far-infrared time-of flight absorption are interpreted time-of flight absorption are interpreted on the basis of the knowledge on the thin sample. The signal observed in far-infrared absorption is due to free exctions and the drift velocity decreases with increasing magnetic fields. In patricular, the velocity at zero magnetic field is 7 * 10^3 cm/s and the free excitons are emitted from the high density plasma or they follow fast diffusing plasma.
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