Abstract

Chemical vapour deposition of two-dimensional materials typically involves the conversion of vapour precursors to solid products in a vapour–solid–solid mode. Here, we report the vapour–liquid–solid growth of monolayer MoS2, yielding highly crystalline ribbons with a width of few tens to thousands of nanometres. This vapour–liquid–solid growth is triggered by the reaction between MoO3 and NaCl, which results in the formation of molten Na–Mo–O droplets. These droplets mediate the growth of MoS2 ribbons in the ‘crawling mode’ when saturated with sulfur. The locally well-defined orientations of the ribbons reveal the regular horizontal motion of the droplets during growth. Using atomic-resolution scanning transmission electron microscopy and second harmonic generation microscopy, we show that the ribbons are grown homoepitaxially on monolayer MoS2 with predominantly 2H- or 3R-type stacking. Our findings highlight the prospects for the controlled growth of atomically thin nanostructure arrays for nanoelectronic devices and the development of unique mixed-dimensional structures.

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Acknowledgements

G.E. acknowledges the Singapore National Research Foundation for funding the research under an NRF Research Fellowship (NRF-NRFF2011-02) and medium-sized centre programme. G.E. also acknowledges support from the Ministry of Education (MOE), Singapore, under AcRF Tier 2 (MOE2015-T2-2-123, MOE2017-T2-1-134). Y.-C.L. and K.S. acknowledge support from JSPS KAKENHI (JP16H06333). T.T. acknowledges support from JSPS KAKENHI (JP16H00922). Jing W. acknowledges A*STAR Pharos Funding from the Science and Engineering Research Council (grant no. 1527200015). F.D. acknowledges support from the Institute for Basic Science (IBS-R019-D1). S.L. acknowledges Y. Sun for helpful discussion and thanks all staff members of the Nanofabrication group at NIMS for their support.

Author information

Affiliations

  1. Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore

    • Shisheng Li
    • , Zhuo Wang
    • , Zehua Hu
    • , Junyong Wang
    • , Leiqiang Chu
    • , Weijie Zhao
    • , Wei Chen
    • , Andrew Thye Shen Wee
    •  & Goki Eda
  2. Department of Physics, National University of Singapore, Singapore, Singapore

    • Shisheng Li
    • , Zhuo Wang
    • , Zehua Hu
    • , Junyong Wang
    • , Qi Zhang
    • , Leiqiang Chu
    • , Weijie Zhao
    • , Wei Chen
    • , Andrew Thye Shen Wee
    •  & Goki Eda
  3. International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan

    • Shisheng Li
    • , Dai-Ming Tang
    • , Takaaki Taniguchi
    •  & Minoru Osada
  4. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan

    • Yung-Chang Lin
    •  & Kazu Suenaga
  5. Center for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan, Republic of Korea

    • Wen Zhao
    •  & Feng Ding
  6. Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore, Singapore

    • Jing Wu
  7. International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, China

    • Zhuo Wang
  8. Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore

    • Youde Shen
  9. Department of Chemistry, National University of Singapore, Singapore, Singapore

    • Hai Zhu
    • , Wei Chen
    • , Qing-Hua Xu
    •  & Goki Eda
  10. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China

    • Chang Liu
  11. Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland

    • Zhipei Sun
  12. QTF Centre of Excellence, Department of Applied Physics, Aalto University, Aalto, Finland

    • Zhipei Sun
  13. Institute of Materials and Systems for Sustainability (iMaSS), Nagoya University, Nagoya, Japan

    • Minoru Osada
  14. Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan

    • Kazu Suenaga
  15. School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea

    • Feng Ding

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Contributions

S.L. designed and conducted the VLS growth. Y.-C.L. and K.S. performed and interpreted the STEM data. S.L., Jing W., Y.S., D.-M.T, C.L., Wen Z., F.D. and G.E. interpreted the VLS growth. Z.W., H.Z., Z.S., Q.-H.X. and A.T.S.W. performed and analysed the SHG data. S.L., Junyong W., Weijie Z. and L.C. studied and analysed the Raman, photoluminescence, AFM and electrical properties. S.L. and Q.Z. performed the TGA and XRD experiments. S.L., Z.H., W.C., T.T. and M.O. conducted the growth of MoX2, WX2 (X = S, Se, Te) from sodium molybdate and sodium tungstate and analysed the growth products. Wen Z. and F.D. carried out the DFT-MD simulations. S.L., Y.-C.L., Wen Z., F.D. and G.E. wrote the paper. All the authors discussed and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding authors

Correspondence to Shisheng Li or Goki Eda.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–13, Supplementary References

  2. Supplementary Video 1

    DFT-MD simulation side-view

  3. Supplementary Video 2

    DFT-MD simulation top-view