Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Sub-10-nm graphene nanoribbons with atomically smooth edges from squashed carbon nanotubes


Graphene nanoribbons are of potential use in the development of electronic and optoelectronic devices. However, the preparation of narrow and long nanoribbons with smooth edges, sizeable bandgaps and high mobilities is challenging. Here we show that sub-10-nm-wide semiconducting graphene nanoribbons with atomically smooth closed edges can be produced by squashing carbon nanotubes using a high-pressure and thermal treatment. With this approach, nanoribbons as narrow as 1.4 nm can be created, and up to 54% of single- and double-walled nanotubes in a sample can be converted into edge-closed nanoribbons. We also fabricate edge-opened nanoribbons using nitric acid as the oxidant to selectively etch the edges of the squashed nanotubes under high pressure. A field-effect transistor fabricated using a 2.8-nm-wide edge-closed nanoribbon exhibits an on/off current ratio of more than 104, from which a bandgap of around 494 meV is estimated. The device also exhibits a field-effect mobility of 2,443 cm2 V−1 s−1 and an on-state channel conductivity of 7.42 mS.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: In situ Raman measurements of the samples undergoing a high-pressure and thermal treatment in a DAC.
Fig. 2: TEM and STEM images of GNRs from squashed CNTs.
Fig. 3: High-resolution STEM characterization of GNRs in treated Samples 1 and 2 and a DWCNT.
Fig. 4: Edge-opened GNRs with the edges selectively etched by HNO3 at high pressure.
Fig. 5: AFM images and Raman measurements of edge-closed GNRs from squashed CNTs.
Fig. 6: Room-temperature electrical measurements of an edge-closed GNR from a squashed DWCNT.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.


  1. 1.

    Schwierz, F. Graphene transistors. Nat. Nanotechnol. 5, 487–496 (2010).

    Article  Google Scholar 

  2. 2.

    Yazyev, O. V. A guide to the design of electronic properties of graphene nanoribbons. Acc. Chem. Res. 46, 2319–2328 (2013).

    Article  Google Scholar 

  3. 3.

    Yang, L., Park, C. H., Son, Y. W., Cohen, M. L. & Louie, S. G. Quasiparticle energies and band gaps in graphene nanoribbons. Phys. Rev. Lett. 99, 186801 (2007).

    Article  Google Scholar 

  4. 4.

    Son, Y. W., Cohen, M. L. & Louie, S. G. Energy gaps in graphene nanoribbons. Phys. Rev. Lett. 97, 216803 (2006).

    Article  Google Scholar 

  5. 5.

    Wang, X. R. et al. Room-temperature all-semiconducting sub-10-nm graphene nanoribbon field-effect transistors. Phys. Rev. Lett. 100, 206803 (2008).

    Article  Google Scholar 

  6. 6.

    Li, X. L., Wang, X. R., Zhang, L., Lee, S. W. & Dai, H. J. Chemically derived, ultrasmooth graphene nanoribbon semiconductors. Science 319, 1229–1232 (2008).

    Article  Google Scholar 

  7. 7.

    Jiao, L. Y., Zhang, L., Wang, X. R., Diankov, G. & Dai, H. J. Narrow graphene nanoribbons from carbon nanotubes. Nature 458, 877–880 (2009).

    Article  Google Scholar 

  8. 8.

    Kimouche, A. et al. Ultra-narrow metallic armchair graphene nanoribbons. Nat. Commun. 6, 10177 (2015).

    Article  Google Scholar 

  9. 9.

    Ma, C. X. et al. Seamless staircase electrical contact to semiconducting graphene nanoribbons. Nano Lett. 17, 6241–6247 (2017).

    Article  Google Scholar 

  10. 10.

    Chen, C. X. et al. Graphene nanoribbons under mechanical strain. Adv. Mater. 27, 303–309 (2015).

    Article  Google Scholar 

  11. 11.

    Xie, L. M. et al. Graphene nanoribbons from unzipped carbon nanotubes: atomic structures, Raman spectroscopy, and electrical properties. J. Am. Chem. Soc. 133, 10394–10397 (2011).

    Article  Google Scholar 

  12. 12.

    Fang, T., Konar, A., Xing, H. L. & Jena, D. Mobility in semiconducting graphene nanoribbons: phonon, impurity, and edge roughness scattering. Phys. Rev. B 78, 205403 (2008).

    Article  Google Scholar 

  13. 13.

    Basu, D., Gilbert, M. J., Register, L. F., Banerjee, S. K. & MacDonald, A. H. Effect of edge roughness on electronic transport in graphene nanoribbon channel metal-oxide-semiconductor field-effect transistors. Appl. Phys. Lett. 92, 042114 (2008).

    Article  Google Scholar 

  14. 14.

    Han, M. Y., Ozyilmaz, B., Zhang, Y. B. & Kim, P. Energy band-gap engineering of graphene nanoribbons. Phys. Rev. Lett. 98, 206805 (2007).

    Article  Google Scholar 

  15. 15.

    Jiao, L. Y., Wang, X. R., Diankov, G., Wang, H. L. & Dai, H. J. Facile synthesis of high-quality graphene nanoribbons. Nat. Nanotechnol. 5, 321–325 (2010).

    Article  Google Scholar 

  16. 16.

    Wang, X. R. et al. Graphene nanoribbons with smooth edges behave as quantum wires. Nat. Nanotechnol. 6, 563–567 (2011).

    Article  Google Scholar 

  17. 17.

    Kosynkin, D. V. et al. Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons. Nature 458, 872–876 (2009).

    Article  Google Scholar 

  18. 18.

    Pan, M. H. et al. Topographic and spectroscopic characterization of electronic edge states in CVD grown graphene nanoribbons. Nano Lett. 12, 1928–1933 (2012).

    Article  Google Scholar 

  19. 19.

    Oliveira, M. H. et al. Synthesis of quasi-free-standing bilayer graphene nanoribbons on SiC surfaces. Nat. Commun. 6, 7632 (2015).

    Article  Google Scholar 

  20. 20.

    Wang, X. R. & Dai, H. J. Etching and narrowing of graphene from the edges. Nat. Chem. 2, 661–665 (2010).

    Article  Google Scholar 

  21. 21.

    Bai, J. W., Duan, X. F. & Huang, Y. Rational fabrication of graphene nanoribbons using a nanowire etch mask. Nano Lett. 9, 2083–2087 (2009).

    Article  Google Scholar 

  22. 22.

    Yu, F. et al. Controlled fabrication of intermolecular junctions of single-walled carbon nanotube/graphene nanoribbon. Small 9, 2405–2409 (2013).

    Article  Google Scholar 

  23. 23.

    Magda, G. Z. et al. Room-temperature magnetic order on zigzag edges of narrow graphene nanoribbons. Nature 514, 608–611 (2014).

    Article  Google Scholar 

  24. 24.

    Yang, W. L., Lucotti, A., Tommasini, M. & Chalifoux, W. A. Bottom-up synthesis of soluble and narrow graphene nanoribbons using alkyne benzannulations. J. Am. Chem. Soc. 138, 9137–9144 (2016).

    Article  Google Scholar 

  25. 25.

    Narita, A. et al. Synthesis of structurally well-defined and liquid-phase-processable graphene nanoribbons. Nat. Chem. 6, 126–132 (2014).

    Article  Google Scholar 

  26. 26.

    Grosse, K. L., Bae, M. H., Lian, F. F., Pop, E. & King, W. P. Nanoscale Joule heating, Peltier cooling and current crowding at graphene–metal contacts. Nat. Nanotechnol. 6, 287–290 (2011).

    Article  Google Scholar 

  27. 27.

    Xia, F. N., Perebeinos, V., Lin, Y.-M., Wu, Y. Q. & Avouris, P. The origins and limits of metal–graphene junction resistance. Nat. Nanotechnol. 6, 179–184 (2011).

    Article  Google Scholar 

  28. 28.

    Huang, B.-C., Zhang, M., Wang, Y. J. & Woo, J. Contact resistance in top-gated graphene field-effect transistors. Appl. Phys. Lett. 99, 032107 (2011).

    Article  Google Scholar 

  29. 29.

    Cai, J. M. et al. Atomically precise bottom-up fabrication of graphene nanoribbons. Nature 466, 470–473 (2010).

    Article  Google Scholar 

  30. 30.

    Ruffieux, P. et al. On-surface synthesis of graphene nanoribbons with zigzag edge topology. Nature 531, 489–492 (2016).

    Article  Google Scholar 

  31. 31.

    Jacobse, P. H. et al. Electronic components embedded in a single graphene nanoribbon. Nat. Commun. 8, 119 (2017).

    Article  Google Scholar 

  32. 32.

    Kolmer, M. et al. Rational synthesis of atomically precise graphene nanoribbons directly on metal oxide surfaces. Science 369, 571–575 (2020).

    Article  Google Scholar 

  33. 33.

    Ma, J., Wang, J. N. & Wang, X. X. Large-diameter and water-dispersible single-walled carbon nanotubes: synthesis, characterization and applications. J. Mater. Chem. 19, 3033–3041 (2009).

    Article  Google Scholar 

  34. 34.

    Qi, H., Qian, C. & Liu, J. Synthesis of high-purity few-walled carbon nanotubes from ethanol/methanol mixture. Chem. Mater. 18, 5691–5695 (2006).

    Article  Google Scholar 

  35. 35.

    Liew, K. M. & Sun, Y. Z. Elastic properties and pressure-induced structural transitions of single-walled carbon nanotubes. Phys. Rev. B 77, 205437 (2008).

    Article  Google Scholar 

  36. 36.

    Elliott, J. A., Sandler, J. K. W., Windle, A. H., Young, R. J. & Shaffer, M. S. P. Collapse of single-wall carbon nanotubes is diameter dependent. Phys. Rev. Lett. 92, 095501 (2004).

    Article  Google Scholar 

  37. 37.

    Mu, W. H., Cao, J. S. & Ou-Yang, Z. C. Shape transition of unstrained flattest single-walled carbon nanotubes under pressure. J. Appl. Phys. 115, 044512 (2014).

    Article  Google Scholar 

  38. 38.

    Gillen, R., Mohr, M., Thomsen, C. & Maultzsch, J. Vibrational properties of graphene nanoribbons by first-principles calculations. Phys. Rev. B 80, 115418 (2009).

    Article  Google Scholar 

  39. 39.

    Talirz, L. et al. On-surface synthesis and characterization of 9-atom wide armchair graphene nanoribbons. ACS Nano 11, 1380 (2017).

    Article  Google Scholar 

  40. 40.

    Peköz, R., Feng, X. L. & Donadio, D. Ab initio characterization of graphene nanoribbons and their polymer precursors. J. Phys.: Condens. Matter 24, 104023 (2012).

    Google Scholar 

  41. 41.

    Borin, B. G. et al. Surface-synthesized graphene nanoribbons for room temperature switching devices: substrate transfer and ex situ characterization. ACS Appl. Nano Mater. 2, 2184–2192 (2019).

    Article  Google Scholar 

  42. 42.

    Fairbrother, A. et al. High vacuum synthesis and ambient stability of bottom-up graphene nanoribbons. Nanoscale 9, 2785–2792 (2017).

    Article  Google Scholar 

  43. 43.

    Sanders, G. D., Nugraha, A. R. T., Saito, R. & Stanton, C. J. Coherent radial-breathing-like phonons in graphene nanoribbons. Phys. Rev. B 85, 205401 (2012).

    Article  Google Scholar 

  44. 44.

    Chen, Z. H., Lin, Y.-M., Rooks, M. J. & Avouris, P. Graphene nano-ribbon electronics. Phys. E 40, 228–232 (2007).

    Article  Google Scholar 

  45. 45.

    Pantano, A. Effects of mechanical deformation on electronic transport through multiwall carbon nanotubes. Int. J. Solids Struct. 122–123, 33–41 (2017).

    Article  Google Scholar 

  46. 46.

    Impellizzeri, A., Briddon, P. & Ewels, C. P. Stacking- and chirality-dependent collapse of single-walled carbon nanotubes: a large-scale density-functional study. Phys. Rev. B 100, 115410 (2019).

    Article  Google Scholar 

  47. 47.

    Llinas, J. P. et al. Short-channel field-effect transistors with 9-atom and 13-atom wide graphene nanoribbons. Nat. Commun. 8, 633 (2017).

    Article  Google Scholar 

  48. 48.

    Murakami, K. et al. Synthesis of graphene nanoribbons from amyloid templates by gallium vapor-assisted solid-phase graphitization. Appl. Phys. Lett. 104, 243101 (2014).

    Article  Google Scholar 

  49. 49.

    Jordan, R. S. et al. Synthesis of graphene nanoribbons via the topochemical polymerization and subsequent aromatization of a diacetylene precursor. Chem 1, 78–90 (2016).

    Article  Google Scholar 

  50. 50.

    Hwang, W. S. et al. Graphene nanoribbon field-effect transistors on wafer-scale epitaxial graphene on SiC substrates. APL Mater. 3, 011101 (2015).

    Article  Google Scholar 

  51. 51.

    Mao, H., Xu, J. & Bell, P. M. Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions. J. Geophys. Res. B 91, 4673 (1986).

    Article  Google Scholar 

Download references


C.C. acknowledges support from the National Natural Science Foundation of China for Excellent Young Scholars (no. 61622404), Chang Jiang (Cheung Kong) Scholars Program of Ministry of Education of China (no. Q2017081), National Natural Science Foundation of China (no. 62074098) and Science and Technology Innovation Action Program from the Science and Technology Commission of Shanghai Municipality (no. 15520720200). Y.L., W.L.M. and the high-pressure DAC experiments were supported by the United States Department of Energy through the Stanford Institute for Materials and Energy Sciences DE-AC02-76SF00515. Work by J.N.W. was supported by the National Key R&D Program of China (2018YFA0208404) and Innovation Program of Shanghai Municipal Education Commission. J.G. was supported by NSF grant nos. 1809770 and 1904580. Work at ORNL was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. W.Z. acknowledges support from the Beijing Outstanding Young Scientist Program (BJJWZYJH01201914430039).

Author information




H.D. and C.C. conceived and designed the experiments and C.C. conceived the theoretical calculations and simulations. C.C. planned and supervised the project. C.C., Y.L., W.Z., M.G., Z.H., F.S., X.L., J.Z.W., J.N.W., F.Y., Q.Z., J.L., G.H., A.L.A. and M.-C.L. performed the experiments and prepared the pristine CNT samples. C.C., Z.H., K.T.L., J.G., W.G. and J.-M.Z. performed the numerical simulations. C.C., Y.L., W.Z., M.G., Z.H., F.S., X.L., J.Z.W., K.T.L., F.Y., Q.Z., J.G., W.G., J.-M.Z., G.H., W.L.M. and H.D. analysed the data and wrote the manuscript. All the authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Changxin Chen, Wendy L. Mao or Hongjie Dai.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Electronics thanks Antonio Pantano, Chee-Tat Toh and An-Ping Li for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–20, Table 1 and Notes 1–3.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Chen, C., Lin, Y., Zhou, W. et al. Sub-10-nm graphene nanoribbons with atomically smooth edges from squashed carbon nanotubes. Nat Electron 4, 653–663 (2021).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing