2021 Fiscal Year Research-status Report
Chirality engineering of single-walled carbon nanotubes by in situ TEM probing
| Project/Area Number |
20K05281
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
湯 代明 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 主任研究員 (50646271)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | chirality alteration / carbon nanotubes / thermomechanical / transition mechanism / nanotube transistors / quantum transport |
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| Outline of Annual Research Achievements |
Carbon nanotubes (CNTs) have a helical structure where the chirality determines them to be metallic or semiconducting. According to the project goal and annual plan to “engineer” the chirality of individual single walled CNTs (SWCNTs) by mechanical and thermal stimuli, and to investigate the chirality transition mechanism by advanced in situ transmission electron microscopy (TEM) probing technique, in situ TEM experiments and theoretical calculations have been conducted.
Research achievements in this year include: (1) A transition trend towards larger chiral angle was discovered and explained in terms of orientation-dependent dislocation formation energy. (2) Controlled metal-to-semiconductor transition was realized to create nanotube transistors with a semiconducting nanotube channel covalently bonded between metallic nanotube source and drain. (3) Coherent quantum transport and Fabry-Perot interference at room temperature was observed for the nanotube transistors with the channel length down to 3 nanometers.
Main results have been published in Science (D.-M. Tang et al., Semiconductor nanochannels in metallic carbon nanotubes by thermomechanical chirality alteration. Science 374, 1616-1620 (2021).)
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The original plan of altering the chirality and elucidating the transition mechanism has been successfully completed.
In addition, by using in situ electrical transport measurement as feedback, controlled metal-to-semiconductor transition was achieved for fabricating metal-semiconductor-metal nanotube junctions and transistors.
Furthermore, nanotube transistors with the channel length down to 3 nm have been fabricated, demonstrating quantum transport at room temperature.
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| Strategy for Future Research Activity |
To further deepen the understanding of the CNT chirality transition mechanism, it is planned to collect large amount of data and to reveal the transition pattern by statistical analysis.
To build a quantitative physical model of the CNT chirality transition, it is planned to measure the thermal effects during the mechanical deformation process, by using electron energy loss spectroscopy (EELS).
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| Causes of Carryover |
Due to the Covid-19 pandemic, it was not possible to make business trips and to attend conferences, also some experiments were rescheduled to the next fiscal year.
It is planned to use the budget from last fiscal year to conduct the measurement of the thermal effects during the CNT chirality transition.
It is planned to attend international conferences in 32nd International Conference on Diamond and Carbon Materials (ICDCM) and MRS Fall 2022-Symp.
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[Presentation] Growth mechanism and handedness relation of one-dimensional van der Waals heterostructures2021
Author(s)
Yongjia Zheng, Akihito Kumamoto, Rong Xiang, Kaoru Hisama, Keigo Otsuka, Yuta Sato, Taiki Inoue, Shohei Chiashi, Daiming Tang, Qiang Zhang, Anton Anisimov, Esko Kauppinen, Kazu Suenaga, Yuichiro Ikuhara, Shigeo Maruyama
Organizer
International Conference on the Science and Application of Nanotubes and Low-Dimensional Materials (NT21)
Int'l Joint Research
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