1996 Fiscal Year Final Research Report Summary
Study on Exciton Interaction and Biexciton Formation Mechanism using Polarized Light
| Project/Area Number |
07640443
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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 |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
HAYASHI Tetsusuke Kyoto University, Department of Fundamental Sciences, Professor, 総合人間学部, 教授 (80026799)
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| Co-Investigator(Kenkyū-buntansha) |
ASHIDA Masaaki Kyoto University, Department of Physics, Research Associate, 理学部, 助手 (60240818)
WATANABE Masayuki Kyoto University, Department of Fundamental Sciences, Research Associate, 総合人間学部, 助手 (20240525)
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| Project Period (FY) |
1995 – 1996
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| Keywords | SEMICONDUCTOR / EXCITON / POLARITON / BIEXCITON |
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| Research Abstract |
The purpose of this research project is to clarify the mechanism of biexciton formation through interaction of exciton polaritons in semiconductors such as PbI_2 and CuCl. The obtained results are as follows.
(1) Efficiency of biexciton formation through interaction of excitons has been compared in PbI_2 crystal and Pb_<1-x>Cd_xI_2 mixed crystals. In the mixed crystal, it was found that localized biexcitons are created and the formation efficiency of biexcitons increases by an order of magnitude from that in pure PbI_2 due to the confinement of excitons in the localized states.
(2) Spectrally-resolved four-wave mixing in the exciton resonance region has been investigated under various combination of two polarized lights from a sub-picosecond pulse laser. Coherent interaction of exciton polaritons was found to be dominated by the polarization selection rule for two-photon transition to the biexciton state.
(3) Dependence of biexciton formation on the crystal thickness has been investigated in CuCl thin crystals embedded in a cleaved wedge of NaF crystal. A huge increase in the biexciton luminescence was observed in a particular range of thickness, indicating the interference effect of polaritons.
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