Carbon nanotube intramolecular junctions


The ultimate device miniaturization would be to use individual molecules as functional devices. Single-wall carbon nanotubes (SWNTs) are promising candidates for achieving this: depending on their diameter and chirality, they are either one-dimensional metals or semiconductors1,2. Single-electron transistors employing metallic nanotubes3,4 and field-effect transistors employing semiconducting nanotubes5 have been demonstrated. Intramolecular devices have also been proposed which should display a range of other device functions6,7,8,9,10,11. For example, by introducing a pentagon and a heptagon into the hexagonal carbon lattice, two tube segments with different atomic and electronic structures can be seamlessly fused together to create intramolecular metal–metal, metal–semiconductor, or semiconductor–semiconductor junctions. Here we report electrical transport measurements on SWNTs with intramolecular junctions. We find that a metal–semiconductor junction behaves like a rectifying diode with nonlinear transport characteristics that are strongly asymmetric with respect to bias polarity. In the case of a metal–metal junction, the conductance appears to be strongly suppressed and it displays a power-law dependence on temperatures and applied voltage, consistent with tunnelling between the ends of two Luttinger liquids. Our results emphasize the need to consider screening and electron interactions when designing and modelling molecular devices. Realization of carbon-based molecular electronics will require future efforts in the controlled production of these intramolecular nanotube junctions.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Tapping-mode atomic force microscope amplitude images of examples of nanotube junction devices.
Figure 2: Current–voltage characteristics across the metal–semiconductor junction of Fig. 1a, showing rectifying behaviour.
Figure 3: Linear-response two-probe conductances G of segments I and II and across the metal–metal junction of Fig. 1b, plotted against temperature T on a double-logarithmic scale.
Figure 4: Large-bias transport characteristics measured across the metal–metal junction of Fig. 1b.


  1. 1

    Wildöer,J. W. G., Venema,L. C., Rinzler,A. G., Smalley,R. E. & Dekker,C. Electronic structure of atomically resolved carbon nanotubes. Nature 391, 59 –62 (1998).

  2. 2

    Odom,T. W., Huang,J., Kim,P. & Lieber,C. M. Atomic structure and electronic properties of single-walled carbon nanotubes. Nature 391, 62–64 ( 1998).

  3. 3

    Tans,S. J. et al. Individual single-wall carbon nanotubes as quantum wires. Nature 386, 474–477 ( 1997).

  4. 4

    Bockrath,M. et al. Single-electron transport in ropes of carbon nanotubes. Science 275, 1922–1925 ( 1997).

  5. 5

    Tans,S. J., Verschueren,A. R. M. & Dekker, C. Room-temperature transistor based on a single carbon nanotube. Nature 393, 49– 52 (1998).

  6. 6

    Chico,L., Crespi,V. H., Benedict,L. X., Louie,S. G. & Cohen,M. L. Pure carbon nanoscale devices: Nanotube heterojunctions. Phys. Rev. Lett. 76, 971 –974 (1996).

  7. 7

    Lambin,Ph., Fonseca,A., Vigneron,J. P., Nagy,J. B. & Lucas,A. A. Structural and electronic properties of bent carbon nanotubes. Chem. Phys. Lett. 245, 85–89 (1995).

  8. 8

    Saito,R., Dresselhaus,G. & Dresselhaus, M. S. Tunnelling conductance of connected carbon nanotubes. Phys. Rev. B 53, 2044– 2050 (1996).

  9. 9

    Charlier,J.-C., Ebbesen,T. W. & Lambin, Ph. Structural and electronic properties of pentagon-heptagon pair defects in carbon nanotubes. Phys. Rev. B 53, 11108–11113 (1996).

  10. 10

    Menon,M. & Srivastava,D. Carbon nanotube “T junctions”: Nanoscale metal-semiconductor-metal contact devices. Phys. Rev. Lett. 79, 4453–4456 ( 1997).

  11. 11

    Chico,L., López Sancho,M. P. & Muñoz,M. C. Carbon-nanotube-based quantum dot. Phys. Rev. Lett. 81, 1278–1281 (1998).

  12. 12

    Iijima,S., Brabec,C. J., Maiti,A. & Bernholc,J. Structural flexibility of carbon nanotubes. J. Chem. Phys. 104, 2089–2092 (1996).

  13. 13

    Yakobson,B. I., Brabec,C. J. & Bernholc, J. Nanomechanics of carbon tubes: Instabilities beyond the linear response. Phys. Rev. Lett. 76, 2511–2514 (1996).

  14. 14

    Collins,P. G., Zettl,A., Bando,H., Thess,A. & Smalley,R. E. Nanotube nanodevice. Science 278, 100–103 (1997).

  15. 15

    Chico,L., Benedict,L. X., Louie,S. G. & Cohen,M. L. Quantum conductance of carbon nanotubes with defects. Phys. Rev. B 54, 2600–2606 ( 1996).

  16. 16

    Bockrath,M. et al. Luttinger-liquid behaviour in carbon nanotubes. Nature 397, 598–601 ( 1999).

  17. 17

    Egger,R. & Gogolin,A. Effective low-energy theory for correlated carbon nanotubes. Phys. Rev. Lett. 79, 5082 –5085 (1997).

  18. 18

    Kane,C., Balents,L. & Fisher,M. P. A. Coulomb interactions and mesoscopic effects in carbon nanotubes. Phys. Rev. Lett. 79, 5086– 5089 (1997).

  19. 19

    Fisher,M. P. A. & Glazman,L. I. in Mesoscopic Electron Transport (eds Kouwenhoven, L. P., Sohn, L. L. & Schön, G.) 331–373 (Kluwer Academic, Boston, 1997).

Download references


We thank R. E. Smalley and co-workers for providing the indispensable single-wall carbon nanotube materials, M. P. Anantram, S. J. Tans and A. A. Odintsov for helpful discussions, V. Meunier for the atomic coordinates used in Fig. 1c, and M. de Jonge and A. van den Enden for experimental assistance. The work was supported by the Dutch Foundation for Fundamental Research on Matter (FOM).

Author information



Corresponding author

Correspondence to Cees Dekker.

Supplementary Information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yao, Z., Postma, H., Balents, L. et al. Carbon nanotube intramolecular junctions. Nature 402, 273–276 (1999).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.