1989 Fiscal Year Final Research Report Summary
Thin-Film Single-Crystal Growth of Layered Materials and Fabrication of The Layered Superlattices by a Hot Wall Technique, and Their Optical Properties
| Project/Area Number |
62460025
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | The University of Tokyo |
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Principal Investigator |
TAKEYAMA Shojiro University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 助手 (20163446)
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| Co-Investigator(Kenkyū-buntansha) |
MIURA Noboru University of Tokyo, Institute for Solid State Physics, Professor, 物性研究所, 教授 (70010949)
KOMATSU Teruo Osaka City University, Department of Physics, Associate Professor, 理学部, 助教授 (90047134)
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| Project Period (FY) |
1987 – 1989
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| Keywords | A Hot Wall Technique / Van-der-Waals Epitaxy / The Layered Material / PbI_2 / BiI_3 Superlattice / Thin-Single-Crystal / Magneto-Optics / High-Pressure Spectroscopy / Stacking Faults |
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| Research Abstract |
A hot wall technique was applied to grow very thin single-crystals of the compound layered materials, PbI_2 and BiI_3, which are the subject of the recent intensive investigations as the representative of the heavy metal halides. The so- called van der Waals epitaxy became possible by employing the layered material as a substrate. The low temperature growth by this method made it possible to grow high quality thin single-crystals. The low temperature absorption spectra of the band-edge direct exciton were used as a probe of the quality of the film. This is confirmed by the transmission electron diffraction and x-ray structural analysis.
It was revealed that the exciton spectra was sensitive to the crystal quality especially for the layer stacking faults and polytypes. Thus it became possible to obtain the films with an optimized thickness for the observation of the direct exciton absorption spectra. As for PbI_2, the inner structure of the exciton were clarified to give the answer for t
… More
he puzzling problem unsolved since 1960 by the successful magneto-optical investigation of the high pulse-magnetic-field spectroscopy. At the same time, new features concerning the exciton-phonon interaction were understood. In the case of BiI_3, the surface exciton was observed for the first time in the absorption measurement due to the high quality of the film surface. The detailed analysis of the band-edge exciton absorption spectra became possible, and new aspects of the exciton dynamics were found correlated to the exciton-phonon interaction. The superlattice PbI_2/BiI_3 were successfully fabricated for the first time by this technique, and the optical properties were investigated, showing interesting features of the exciton in the new superlattice. The quantum size effect was observed on the exciton of PbI_2 by the BiI_3 barrier potential. The electrical energy structure are now under investigation using high-field magneto-optical and high-pressure investigation on the absorption and luminescence of the exciton in this system. Less
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