2001 Fiscal Year Final Research Report Summary
Research for the characteristic 1D electronic atates and optical responses in carbon nanotubes
| Project/Area Number |
12640310
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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 | Konan University (2001)
Nagoya University (2000) |
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Principal Investigator |
ICHIDA Masao Konan University, Department of Science and Engineering, Professor, 理工学部, 講師 (30260590)
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| Co-Investigator(Kenkyū-buntansha) |
HAMANAKA Yasushi Nagoya University, Center for Integrated Research for Science and Engineering, Assistant Professor, 理工学総合研究所, 助手 (20280703)
NAKAURA Arao Nagoya University, Center for Integrated Research for Science and Engineering, Professor, 理工学総合研究所, 教授 (50159068)
ANDO Hiroaki Konan University, Department of Science and Engineering, Professor, 理工学部, 教授 (50330402)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Carbon nanotubes / one-dimensional exciton / optical anisotropy / relaxation dynamics |
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| Research Abstract |
We have investigated the electornic structure and optical properties in single-walled carbon nanotubes. The obtained results are listed as follows.
1. We have measured the absorption spectra of thin-film samples of single-walled carbon nanotubes (SWNTs) with various mean tube diameter. The absorption bands shift to the higher energy side with decreasing mean tube diameter.
2. We have observed diameter-dependent Coulomb effects in the optical transition of semiconducting SWNTs.
3. We have prepared aligned sample of SWNTs in polymer. The optical (absorption and Raman) spectra strongly show the optical anisotropy which was predicted by theoretical works.
4. We have performed femtosecond transient absorption spectroscopy for SWNT thin film samples. The bleaching of absorption bands are observed after photoexcitation. The bleaching recovers within 〜1 ps, and the decay time depends on the tube diameter. This result suggests that the strength of electron-phonon interaction depends on the tube diameter : it becomes stronger with smaller tube diameter.
5. We have investigated the polymerization processes in fullerenes C_<60> and C_<70> crystals. For C_<60> crystals, we have investigated the temporal behavior of photopolymerization process by time resolved Raman spectroscopy.The dimer C_<120> plays a inportant role as intermidiate states in polymerization. We also have controled the photopolymerization process by applied pressure. For Cyo crystals, we have clarified the condition of high temperature-high-pressure polymeriz ation.
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