Development of atomic-scale characterization for low-dimensional materials

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H04797
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Nanostructural physics
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Senga Ryosuke 国立研究開発法人産業技術総合研究所, 材料・化学領域, 主任研究員 (80713221)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: ナノ材料 / 透過電子顕微鏡 / 電子エネルギー損失分光 / カーボンナノチューブ / グラフェン / 励起子 / フォノン

Outline of Final Research Achievements

The optical absorption of a single carbon nanotube has been successfully measured by high-energy-resolution electron energy-loss spectroscopy. We have also established an analytical method to quantitatively link the electron valence excitation spectrum with the optical absorption spectrum. Then we have quantitatively clarified the modulation of optical conductivity at a local defect in a single carbon nanotube. Furthermore, we have developed a technique to investigate vibrational properties using angle-resolved electron energy loss spectroscopy and demonstrated for the first time to measure the phonon dispersion of a single layer graphene. These results were published in eight international journals including Nature, Nanoletters and Physical Review Letters, as well as in seven domestic and international invited talks.

Free Research Field

ナノ材料

Academic Significance and Societal Importance of the Research Achievements

本研究によって低次元材料の物性を決める励起子やフォノンといった準粒子の振る舞いを原子構造と一対一で結び付けることができた。これらの成果は基礎学術的な理解を深めるだけでなく、低次元材料の応用展開を考えるうえでも重要な知見である。例えば微小光源、単一光子エミッタ、高感度光センサーといったデバイスに関して、許容できる欠陥の種類や個数などの指針を与え最適な構造設計に貢献できる。またこれまで理論計算が先行していたナノ材料の格子振動の計測に成功したことも、材料科学分野に大きなインパクトを与える成果であり、熱電素子や光電子デバイス、超電導体などの今後の研究開発への貢献が期待できる。