ナノグラフェン・遷移金属カルコゲナイドにおける新規光物性の開拓

• Project Area: Science of Atomic Layer Systems
• Project/Area Number: 26107522
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Kyoto University
• Principal Investigator: 松田 一成 京都大学, エネルギー理工学研究所, 教授 (40311435)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥7,020,000 (Direct Cost: ¥5,400,000、Indirect Cost: ¥1,620,000); Fiscal Year 2015: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2014: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
• Keywords: 原子層物質 / 光物性 / 励起子 / 荷電励起子 / 原子層 / 遷移金属ダイカルコゲナイド / ナノグラフェン

Outline of Annual Research Achievements

単原子層物質は、グラフェンのディラック電子系、遷移金属カルコゲナイド（MX2; M=Mo, W X=S, Se, Te）における波数空間上での谷（バレー）とスピン自由度の特異性など、多彩な物性発現の舞台である。本研究では、ナノグラフェン、単層遷移金属カルコゲナイドなどの単原子層物質を舞台に、谷（バレー）とスピン自由度が関与する新たな光物性の開拓を目指した。一連の遷移金属ダイカルコゲナイドMX2では、物質ごとにスピン軌道相互作用の大きさやバンド構造が異なるため、ここではバレースピン分極に関する測定がなされていないMoTe2を対象に円偏光励起による偏光分解の発光測定などを行った。
機械剥離により作製された単層MoTe2の発光スペクトルを極低温から室温まで測定した。その結果、極低温では荷電励起子（トリオン）と励起子からの発光ピークが観測された。さらに、発光スペクトルの温度依存性から励起子発光スペクトルの線幅が広がる様子が観測された。発光スペクトルの線幅は、励起子の位相緩和時間の情報を含んでおり、温度上昇とともに励起子の位相緩和時間が短くなることがわかった。これらの結果から、位相緩和のメカニズムに励起子が音響フォノンによって散乱されるプロセスが支配的であることが明らかとなった。さらに、偏光分解の発光測定からMoTe2のバレースピン分極は極低温で40%程度であることが明らかとなった。また、その温度依存性などから、遷移金属ダイカルコゲナイドで最も典型的なMoS2と同様な振る舞いであることがわかった。このことはモリブデンベースの遷移金属ダイカルコゲナイドMoX(X=S, Se, Te)において、S, Teが類似したバレースピン分極の振る舞いをしていることが明らかとなった。さらに、TypeIと呼ばれるバンド構造を有するMoTe2をベースにしたMoTe2/WSe2原子層人工ヘテロ構造の作製に成功した。

Research Progress Status

27年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

27年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] シンガポール国立大学(シンガポール)
• [Journal Article] Homogeneous linewidth broadening and exciton dephasing mechanism in MoTe2 (2016)
  • Author(s): S. Koirala, S. Mouri, Y. Miyauchi, K. Matsuda
  • Journal Title: Physical Review B Volume: 93 Issue: 7 Pages: 075411-075411
  • DOI: 10.1103/physrevb.93.075411
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Exciton-plasmon coupling and electromagnetically induced transparency in monolayer semiconductor hybridized with Ag nanoparticels (2016)
  • Author(s): W. Zhao, S. Wang, B. Liu, I. Verzhbitskiy, S. Li, F. Giustiano, D. Kozawa, K. P. Loh, K. Matsuda, K. Okamoto, R. F. Oulton, and G. Eda
  • Journal Title: Adv. Mat. Volume: 28 Issue: 14 Pages: 2709-2715
  • DOI: 10.1002/adma.201504478
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Fabrication and In Situ Transmission Electron Microscope Characterization of Free-Standing Graphene Nanoribbon Devices (2016)
  • Author(s): Q. Wang, R. Kitaura, S. Suzuki, Y. Miyauchi, K. Matsuda, Y. Yamamoto, S. Arai, H. Shinohara
  • Journal Title: ACS Nano Volume: 10 Issue: 1 Pages: 1475-1480
  • DOI: 10.1021/acsnano.5b06975
  • Peer Reviewed
• [Journal Article] Efficient near-infrared up-conversion photoluminescence in carbon nanotubes (2015)
  • Author(s): N. Akizuki, S. Aota, S. Mouri, K. Matsuda, Y. Miyauchi
  • Journal Title: Nature Communications Volume: 6 Issue: 1 Pages: 8920-8920
  • DOI: 10.1038/ncomms9920
  • NAID: 120005670980
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Enhanced photovoltaic performances of graphene/Si solar cells by insertion of MoS2 thin film (2015)
  • Author(s): Y. Tsuboi, F.Wang, D. Kozawa, K. Funahashi, S. Mouri, Y. Miyauchi, T. Takenobu, K. Matsuda
  • Journal Title: Nanoscale Volume: 7 Issue: 34 Pages: 14476-14482
  • DOI: 10.1039/c5nr03046c
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Optical properties of atomically thin layered transition metal dichalchogenide (2015)
  • Author(s): K. Matsuda
  • Journal Title: J. Phys. Soc. Jpn Volume: 84 Issue: 12 Pages: 121009-121009
  • DOI: 10.7566/jpsj.84.121009
  • NAID: 210000133749
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Considerably improved photovoltaic performance of ​carbon nanotube-based solar cells using metal oxide layers (2015)
  • Author(s): F. Wang, D. Kozawa, Y. Miyauchi, K. Hiraoka, S. Mouri, Y. Ohno, and K. Matsuda
  • Journal Title: Nature Commn. Volume: 6 Issue: 1 Pages: 6305-6305
  • DOI: 10.1038/ncomms7305
  • Peer Reviewed / Open Access
• [Journal Article] Excitonic photoluminescence from nanodisc states in graphene oxides (2014)
  • Author(s): D. Kozawa, X. Zhu, Y. Miyauchi, S. Mouri, M. Ichida, H. Su, K. Matsuda
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 5 Issue: 10 Pages: 1754-1759
  • DOI: 10.1021/jz500516u
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Drastic change in photoluminescence properties of graphene quantum dots by chromatographic separation (2014)
  • Author(s): N. Fuyuno, D. Kozawa, Y. Miyauchi, S. Mouri, R. Kitaura, H. Shinohara, T. Yasuda, N. Komatsu, K. Matsuda
  • Journal Title: Advanced Optical Materials Volume: 2 Issue: 10 Pages: 983-989
  • DOI: 10.1002/adom.201400200
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Photocarrier relaxation pathway in two-dimensional semiconducting transition metal dichalcogenides (2014)
  • Author(s): D. Kozawa, R. Kumar, A. Carvalho, K. K. Amara, W. Zhao, S. Wang, M. Toh, R. M. Ribeiro, A. H. Castro Neto, K. Matsuda and G. Eda
  • Journal Title: Nat. Commun. Volume: 5 Issue: 1 Pages: 4543-4543
  • DOI: 10.1038/ncomms5543
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Nonlinear photoluminescence in atomically thin layered WSe2 arising from diffusion-assisted exciton-exciton annihilation (2014)
  • Author(s): S. Mouri, Y. Miyauchi, M. Toh, W. Zhao, G. Eda, K. Matsuda
  • Journal Title: Physical Review B Volume: 90 Issue: 15 Pages: 155449-155449
  • DOI: 10.1103/physrevb.90.155449
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Nonlinear photoluminescence spectroscopy of carbon nanotubes with localized exciton states (2014)
  • Author(s): M. Iwamura, N. Akizuki, Y. Miyauchi, S. Mouri, J. Shaver, Z. Gao, L. Cognet, B. Lounis, K. Matsuda
  • Journal Title: ACS Nano Volume: 8 Issue: 11 Pages: 11254-11260
  • DOI: 10.1021/nn503803b
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Nonlinear photoluminescence properties of trions in hole-doped single-walled carbon nanotubes (2014)
  • Author(s): N. Akizuki, M. Iwamura, S. Mouri, Y. Miyauchi, T. Kawasaki, H. Watanabe, T. Suemoto, K. Wanatabe, K. Asano, K. Matsuda
  • Journal Title: Physical Review B Volume: 89 Issue: 19 Pages: 195432-195432
  • DOI: 10.1103/physrevb.89.195432
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Rayleigh scattering studies on inter-layer interactions in structure-defined individual double-wall carbon nanotubes (2014)
  • Author(s): S. Zhao, T. Kitagawa, Y. Miyauchi, K. Matsuda, H. Shinohara, and R. Kitaura
  • Journal Title: Nano Research Volume: 7 Issue: 10 Pages: 1548-1555
  • DOI: 10.1007/s12274-014-0515-y
  • Peer Reviewed
• [Journal Article] Redox properties of a single (7,5)single-walled carbon nanotube determined by in situ photoluminescence spectroelectrochemical method (2014)
  • Author(s): L. Hong, S. Mouri, Y. Miyauchi, K. Matsuda, N. Nakashima
  • Journal Title: Nanoscale Volume: 6 Issue: 21 Pages: 12798-12804
  • DOI: 10.1039/c4nr03945a
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Novel optical properties of nano-carbon and two-dimensional materials (2016)
  • Author(s): K. Matsuda
  • Organizer: The 3rd Muju international Winter School
  • Place of Presentation: Muju, Korea
  • Year and Date: 2016-01-17
  • Int'l Joint Research / Invited
• [Presentation] Novel optical properties and application of atomically thin two-dimensional material and its hetero-structure (2015)
  • Author(s): K. Matsuda
  • Organizer: CEMS Topical Meeting on Emergent 2D Materials
  • Place of Presentation: Wako, Japan
  • Year and Date: 2015-12-11
  • Int'l Joint Research / Invited
• [Presentation] Novel optical properties of monolayer transition metal dichalcogenide (2015)
  • Author(s): K. Matsuda
  • Organizer: 6th A3 symposium on Energy Materials
  • Place of Presentation: Fukuoka, Japan
  • Year and Date: 2015-11-09
  • Int'l Joint Research / Invited
• [Presentation] undamental optical properties and optical device application of 2D materials (2015)
  • Author(s): K. Matsuda
  • Organizer: 2015 International Conference on Solid State Devices and Materials
  • Place of Presentation: Hokaido, Japan
  • Year and Date: 2015-09-27
  • Int'l Joint Research / Invited
• [Presentation] Novel excitonic properties arising from excitons and trions in nano-carbon and atomically thin layered materials (2015)
  • Author(s): K. Matsuda
  • Organizer: 6th Workshop of Nanotube Optics and Nanospectroscopy
  • Place of Presentation: Konster Banz, Germany
  • Year and Date: 2015-06-01
  • Int'l Joint Research / Invited
• [Presentation] Novel excitonic properties of nano-carbon and atomically thin layered materials (2015)
  • Author(s): K. Matsuda
  • Organizer: 11th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials
  • Place of Presentation: Montreal, Canada
  • Year and Date: 2015-05-18
  • Int'l Joint Research / Invited
• [Presentation] ナノカーボン物質・原子層物質におけるナノ光科学とその応用 (2015)
  • Author(s): 松田一成
  • Organizer: 第48 回フラーレン・ ナノチューブ・グラフェン総合シンポジウム
  • Place of Presentation: 東京大学、東京
  • Year and Date: 2015-02-21 – 2015-02-23
  • Invited
• [Presentation] ナノカーボン物質・原子層物質のナノ 光科学とその応用 (2015)
  • Author(s): 松田一成
  • Organizer: 「先端物質科学と限界光駆動」 研究会
  • Place of Presentation: 京都大学、京都
  • Year and Date: 2015-01-10 – 2015-01-11
  • Invited
• [Presentation] 原子層薄膜物質の光科学 (2014)
  • Author(s): 松田一成
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学、北海道
  • Year and Date: 2014-09-17 – 2014-09-20
  • Invited
• [Presentation] Physics of local quantum states in carbon nanotubes for photonic applications (2014)
  • Author(s): Y. Miyauchi and K. Matsuda
  • Organizer: Active Photonic Materials VI Conference
  • Place of Presentation: San Diego Convention Center, USA
  • Year and Date: 2014-08-17 – 2014-08-21
  • Invited
• [Presentation] Novel optical properties of carbon nanotubes and atomically thin-layered materials (2014)
  • Author(s): K. Matsuda
  • Organizer: The 6th IEEE international Nanoelectronics Conference 2014 (IEEE INEC2014)
  • Place of Presentation: Hokkaido University, Hokkaido
  • Year and Date: 2014-07-28 – 2014-07-31
  • Invited
• [Presentation] ナノカーボン物質(酸化グラフェン・グラフェンナノ構造)の光科学 (2014)
  • Author(s): 松田一成
  • Organizer: 第2回酸化グラフェンシンポジウム
  • Place of Presentation: 熊本大学、熊本
  • Year and Date: 2014-06-24
  • Invited
• [Presentation] Photophysics of carbon nanotubes with local luminescent states (2014)
  • Author(s): Y. Miyauchi and K. Matsuda
  • Organizer: 8th International Workshop on Metrology, Standardization and Industrial Quality of Nanotubes
  • Place of Presentation: University of Southern California, USA
  • Year and Date: 2014-06-02 – 2014-06-06
  • Invited
• [Presentation] ナノカーボン, 単原子層物質のナノ光科学 (2014)
  • Author(s): 松田一成
  • Organizer: 応用物理学会「シリコンテクノロジー分科会第172回研究集会」
  • Place of Presentation: 産業技術総合研究所、筑波
  • Year and Date: 2014-05-23
  • Invited
• [Presentation] Strong nonlinear photoluminescence properties of trions in single-walled carbon nanotubes (2014)
  • Author(s): K. Matsuda
  • Organizer: 225rd The Electrochemical Society (ECS) Meeting
  • Place of Presentation: Hilton Bonnet Creak, USA
  • Year and Date: 2014-05-11 – 2014-05-15
  • Invited