1998 Fiscal Year Final Research Report Summary
Growth of Urtra-thin Films and Their Nonlinear Optical Response in Layered Semiconductors
| Project/Area Number |
08454084
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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 | 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 | Osaka City University |
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Principal Investigator |
KOMATSU Teruo Faculty of Science, Osaka City University, Professor, 理学部, 教授 (90047134)
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| Co-Investigator(Kenkyū-buntansha) |
AKAI Ichiro Faculty of Science, Osaka City University, Lecturer, 理学部, 講師 (20212392)
唐沢 力 大阪市立大学, 理学部, 教授 (90106336)
IIDA Takeshi Faculty of Science, Osaka City University, Professor, 理学部, 教授 (80047191)
KOMATSU Teruo Faculty of Science, Osaka City University, Professor (90047134)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Hot-wall method / urtra thin films / BiI_3 / Van der waals epitaxtial growth / linear optical response / nonlinear optical response / high density excitions / 非線形光学応答 |
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| Research Abstract |
We'v prepared very thin micro-crystals of BiI_3 on the creaved substrate of CdI_2 single crystals and on the (1ll) creaved surface of CaF_2 single crystals by using a Hotwall method. The microcrystallites having a disk-like shape with mono-layer thickness were grown in CdI_2 matrices. In these crystals we have studied structural characteristics by using a transmission electron microscope and AFM technique in connection with optical properties and behavior of the excitons at high density.
The exciton absorption band with narrow line width similar in bulk crystals was observed in the samples with the thickness of 300 A of BiI_3 grown on the substrate of creaved CdI_2 crystals. New absorption band appeared and resonant luminescence band at 2.02eV was observed in the case of the sample with very small evaporation rate of BiI_3 on the (111) creaved surface of CaF_2 single crystals by using a Hotwall method.
For the resonant excitation at the microcrystallite bands in CdI_2 matrices, luminescence bands appear with Stokes shifts. A quantum disk model in which the center of mass motion of the exciton is confined and a theory of the size-dependent exciton-acoustic phonon interaction in the quantum disks have been developed. Nonlinear optical rsponse of the excitons in such microcrystallites with thin layer thickness have been investigated. From the analysis of the excitation energy dependence of the luminescence spectra, stability of the biexciton states in microcrystaliites was discussed.
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