Towards the synthesis of semiconducting single-walled carbon nanotubes by floating-catalyst chemical vapor deposition: Challenges of reproducibility

Er Xiong Ding, Peng Liu, Abu Taher Khan, Qiang Zhang*, Nan Wei, Hua Jiang, Esko I. Kauppinen

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)
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High-purity semiconducting single-walled carbon nanotubes (s-SWCNTs) are of paramount significance for the fabrication of high-performance electronics. Here, we present continuous production of high-purity, long, and isolated s-SWCNTs by gas-phase synthesis, retaining the pristine morphologies of as-synthesized nanotubes. The s-SWCNTs were synthesized at ca. 920 °C using ethanol and methanol as carbon source and growth enhancer, respectively in N2 and H2. The purity of as-produced s-SWCNTs with a mean length of 15.2 μm can reach 98% as determined by optical absorption spectroscopy. We observed that the overpressure in the reactor and methanol are the principal causes of the enrichment of s-SWCNTs. Specifically, the s-SWCNTs were found to be more negatively charged, and oxygen-contained species play critical roles in the s-SWCNT synthesis. Through the demonstration of field-effect transistors, the s-SWCNTs exhibit a high mean charge carrier mobility of 453.3 cm2 V−1 s−1 which is 2.27 times higher than that of the transistors fabricated with high-quality dispersion-processed SWCNTs. Additionally, we discuss the challenges of synthesis repeatability and recommend a few tips to improve reproducibility. Our study represents an important step towards the scalable production of clean, long, and isolated s-SWCNTs with high purity and narrow bandgap distribution.

Original languageEnglish
Pages (from-to)92-100
Number of pages9
Publication statusPublished - 15 Aug 2022
MoE publication typeA1 Journal article-refereed


  • Gas-phase synthesis
  • Methanol
  • Pressure
  • Reproducibility
  • Semiconducting single-walled carbon nanotubes


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  • CNTstress/Kauppinen

    Kauppinen, E., Ahmad, S., Zhang, Q., Tavakkoli, M. & Khan, M.


    Project: Academy of Finland: Other research funding

  • FEDOC / Koskinen

    Koskinen, J., Wester, N., Durairaj, V., Johansson, L. & Etula, J.


    Project: Business Finland: Other research funding

  • CNT-PV

    Zhang, Q., Kauppinen, E. & Wei, N.


    Project: Business Finland: Other research funding

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