2018 Fiscal Year Annual Research Report
| Project/Area Number |
18F18350
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
末永 和知 国立研究開発法人産業技術総合研究所, 材料・化学領域, 首席研究員 (00357253)
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| Co-Investigator(Kenkyū-buntansha) |
GOGOI PRANJAL KUMAR 国立研究開発法人産業技術総合研究所, 材料・化学領域, 外国人特別研究員
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| Project Period (FY) |
2018-10-12 – 2021-03-31
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| Keywords | EELS / STEM / TMDC / vdW heterostructure / Dielectric function / Optical absorption |
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| Outline of Annual Research Achievements |
We have performed high spatial and energy resolution low-loss electron energy loss spectroscopy (EELS) on transition metal dichalcogenide (TMDC) van der Waals heterostructures to reveal how the absorption spectra depend on the relative orientation of the layers. A manuscript is under review in ACS Nano, based on these results. We have new results on the mapping of the absorption spectra in Moire superlattices of aligned heterostructures. Similarly, we have obtained temperature-dependent absorption spectra of heterostructures to reveal the effect of thermal energy on the interlayer coupling. We have preliminary results on momentum-resolved low-loss EELS of TMDC monolayers, low-loss EELS of TMDC nanoribbons and nanotubes, which would lead to full-fledged publications in the near future.
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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
We have made good progress and we are on the right track in the research work undertaken during this JSPS fellowship period until now. The focus is on electron energy loss spectroscopy of two-dimensional materials. During the last eight-month period of the fellowship, extensive familiarization to the three state-of-the-art electron microscopes and advanced TEM sample preparation methods were received. Now, we have a strong foundation for high quality research output in the next stages of the fellowship. We already have some excellent results and a manuscript based on these is currently under review for publication. The immediate goal is thorough completion of few undergoing projects with promising preliminary results and to perform impactful new experiments in both TEM and STEM mode.
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| Strategy for Future Research Activity |
The primary focus of our research in this year will be on investigating the optical properties of 2D transition metal dichalcogenides (TMDCs) and their heterostructures at high spatial, energy, and momentum resolutions. We have substantial preliminary results on various specific project based on these general themes, and the goal will be to publish some excellent articles based on thorough and complete studies. Temperature-dependent measurements are planned in most cases. We will also focus on the general theoretical aspects of the efficient zero-loss subtraction from the low-loss EELS data for these materials for accurately extracting the dielectric function. Modification of the Kramers- Kronig analysis applicable for the two dimensional case is an important requirement in this direction.
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Research Products
(3 results)
