2022 Fiscal Year Annual Research Report
Tip enhanced Terahertz - Raman for investigating graphene-water interactions at the nanoscale
| Project/Area Number |
21F21033
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| Allocation Type | Single-year Grants |
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
金 有洙 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (50373296)
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| Co-Investigator(Kenkyū-buntansha) |
JACULBIA RAFAEL 国立研究開発法人理化学研究所, 開拓研究本部, 外国人特別研究員
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| Project Period (FY) |
2021-09-28 – 2024-03-31
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| Keywords | graphene / STM / tip enhancement / Raman spectroscopy / defect / strain |
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| Outline of Annual Research Achievements |
For this project, graphene grown on Au(111) surface via chemical vapour deposition was investigated. Samples were investigated using STM, STS and STM-TERS. STM imaging revealed the honeycomb structure and Moire patterns typically observed in graphene. The STM-TERS spectra showed the G, D and 2D band of graphene. Moreover, the spectra showed a splitting of the G-band which we attribute to a combination of uniaxial strain, and the presence of defects on the graphene layer. Apart from single point STM-TERS measurement, we were also able to perform STM-TERS mapping. Because of weak Raman signals, STM-TERS mapping is challenging as it required long acquisition times. For this, we utilized the automated remote experiment system we designed. This allowed us to conveniently and safely perform the experiment while not being physically present in the experimental room. The results of the mapping revealed the presence of a domain boundary which was not observed in the STM images.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In this project we have built a setup for obtaining tip-enhanced Terahertz Raman spectroscopy based on the STM. We investigated Graphene Samples grown on Au(111) via CVD using STM-Tip enhanced Raman spectroscopy. The STM-TERS spectra showed the typical peaks expected for graphene samples, except that the G-band showed splitting. STM-TERS mapping revealed that there is some residual strain possible introduced during growth owing to the lattice mismatch between the graphene layer and the Au (111) substrate. Our results reveal that STM-TERS imaging is effective in revealing the strain in CVD grown Graphene samples.
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| Strategy for Future Research Activity |
In the future, we intend to apply our technique to investigate other 2D materials and single molecules in order to discover more information about their interactions.
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