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.

Efficient photovoltage multiplication in carbon nanotubes


Carbon nanotubes are direct-bandgap materials that are not only useful for nanoelectronic applications1,2, but also have the potential to make a significant impact on the next generation of photovoltaic technology3,4,5. A semiconducting single-walled carbon nanotube (SWCNT) has an unusual band structure, as a result of which high-efficiency carrier multiplication effects have been predicted and observed6,7 and films of SWCNTs with absorption close to 100% have been reported8. Other features that are also important for photovoltaic applications include high mobility9,10 and the availability of ohmic contacts for both electrons11,12 and holes13. However, the photovoltage generated from a typical semiconducting SWCNT is less than 0.2 V, which is too small for most practical photovoltaic applications. Here, we show that this value may be readily multiplied by using virtual contacts at the carbon nanotube. In one example, more than 1.0 V is generated from a 10-μm-long carbon nanotube with a single-cell photovoltage of 0.2 V.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Structure and performance of a CNT-based photovoltaic device.
Figure 2: Structure and performance of CNT-based double-cell photovoltaic modules.
Figure 3: Structure and characteristics of cascaded CNT photovoltaic modules.


  1. 1

    Charlier, J. C., Blase, X. & Roche, S. Electronic and transport properties of nanotube. Rev. Mod. Phys. 79, 677–732 (2007).

    ADS  Article  Google Scholar 

  2. 2

    Javey, A. & Kong, J. (eds) Carbon Nanotube Electronics (Springer, 2009).

    Google Scholar 

  3. 3

    Avouris, Ph., Freitag, M. & Perebeinos, V. Carbon-nanotube photonics and optoelectronics. Nature Photon. 2, 341–350 (2008).

    ADS  Article  Google Scholar 

  4. 4

    Zhu, H. W., Wei, J. Q., Wang, K. L. & Wu, D. H. Applications of carbon materials in photovoltaic solar cells. Solar Energy Mater. Solar Cells 93, 1461–1470 (2009).

    Article  Google Scholar 

  5. 5

    Chen, C., Lu, Y., Kong, E. S., Zhang, Y. F. & Lee, S. T. Nanowelded carbon-nanotube based solar microcells. Small 4, 1313–1318 (2008).

    Article  Google Scholar 

  6. 6

    Nozik, A. J. Nanoscience and nanostructures for photovoltaics and solar fuels. Nano Lett. 10, 2735–2741 (2010).

    ADS  Article  Google Scholar 

  7. 7

    Gabor, N. M., Zhong, Z. H., Bosnick, K., Park, J. & McEuen, P. L. Extremely efficient multiple electron–hole pair generation in carbon nanotube photodiodes. Science 325, 1367–1371 (2010).

    ADS  Article  Google Scholar 

  8. 8

    Yang, Z. P., Ci, L. J., Bur, J. A., Lin, S. Y. & Ajayan, P. M. Experimental observation of an extremely dark material made by a low-density nanotube array. Nano Lett. 8, 446–451 (2008).

    ADS  Article  Google Scholar 

  9. 9

    Durkop, T., Getty, S. A., Cobas, E. & Fuhrer, M. S. Extraordinary mobility in semiconducting carbon nanotube. Nano Lett. 4, 35–39 (2004).

    ADS  Article  Google Scholar 

  10. 10

    Saito, R., Dresselhaus, G. & Dresselhaus, M. S. Physical Properties of Carbon Nanotubes (Imperial College Press, 1998).

    Book  Google Scholar 

  11. 11

    Zhang, Z. Y. et al. Self-aligned ballistic n-type single-walled carbon nanotube field-effect transistors with adjustable threshold voltage. Nano Lett. 8, 3696–3701 (2008).

    ADS  Article  Google Scholar 

  12. 12

    Ding, L. et al. Y-contacted high-performance n-type single-walled carbon nanotube field-effect transistors: scaling and comparison with Sc-contacted devices. Nano Lett. 9, 4209–4214 (2009).

    ADS  Article  Google Scholar 

  13. 13

    Javey, A., Guo, J., Wang, Q., Lundstrom, N. & Dai, H. J. Ballistic carbon nanotube field-effect transistors. Nature 424, 654–657 (2003).

    ADS  Article  Google Scholar 

  14. 14

    Nelson, J. The Physics of Solar Cells (Imperial College Press, 2003).

    Book  Google Scholar 

  15. 15

    Zhou, C. W., Kong, J., Yenilmez, E. & Dai, H. J. Modulated chemical doping of individual carbon nanotube. Science 290, 1552–1555 (2000).

    ADS  Article  Google Scholar 

  16. 16

    Lee, J. U., Gipp, P. P. & Heller, C. M. Carbon nanotube p–n junction diodes. Appl. Phys. Lett. 85, 145–147 (2004).

    ADS  Article  Google Scholar 

  17. 17

    Mueller, T. et al. Efficient narrow-band light emission from a single carbon nanotube p–n diode. Nature Nanotech. 5, 27–31 (2010).

    ADS  Article  Google Scholar 

  18. 18

    Avouris, Ph. et al. Carbon nanotube electronics and optoelectronics. IEDM Tech. Digest 04, 525–529 (2004).

    Google Scholar 

  19. 19

    Wang, S. et al. A doping-free carbon nanotube CMOS inverter-based bipolar diode and ambipolar transistor. Adv. Mater. 20, 3258–3262 (2008).

    Article  Google Scholar 

  20. 20

    Wang, S. et al. High-performance carbon nanotube light-emitting diodes with asymmetric contacts. Nano Lett. 11, 23–29 (2011).

    ADS  Article  Google Scholar 

  21. 21

    Lee, J. U. Photovoltaic effect in ideal carbon nanotube diodes. Appl. Phys. Lett. 87, 073101 (2005).

    ADS  Article  Google Scholar 

  22. 22

    Komp, R. J. Practical Photovoltaics Electricity from Solar Cells (AATEC Publications, 2001).

    Google Scholar 

  23. 23

    Yao, Y. et al. Temperature mediated growth of single-walled carbon nanotube intramolecular junctions. Nature Mater. 6, 283–286 (2007).

    ADS  Article  Google Scholar 

  24. 24

    Pei, T. et al. Temperature performance of doping-free top-gate CNT field-effect transistors: potential for low- and high-temperature electronics. Adv. Funct. Mater. 21, 1843–1849 (2011).

    Article  Google Scholar 

  25. 25

    Ghosh, S., Bachilo, S. M. & Weisman, R. B. Advanced sorting of single-walled carbon nanotubes by nonlinear density-gradient ultracentrifugation. Nature Nanotech. 5, 443–450 (2010).

    ADS  Article  Google Scholar 

  26. 26

    Liu, H., Nishide, D., Tanaka, T. & Kataura, H. Large-scale single-chirality separation of single-wall carbon nanotubes by simple gel chromatograph. Nat. Commun. 2, 309-1-8 (2011).

    ADS  Google Scholar 

  27. 27

    Engel, M. et al. Thin film nanotube transistors based on self-assembled, aligned, semiconducting carbon nanotube arrays. ACS Nano 2, 2445–2452 (2008).

    Article  Google Scholar 

  28. 28

    Zhou, W. W. et al. Copper catalyzing growth of single-walled carbon nanotubes on substrates. Nano Lett. 6, 2987–2990 (2006).

    ADS  Article  Google Scholar 

Download references


This work was supported by the Ministry of Science and Technology (grant nos 2011CB933002 and 2011CB933001), the Fundamental Research Funds for the Central Universities, and National Science Foundation of China (grant nos 61071013, 61001016, 51072006 and 60971003).

Author information




L.J.Y. and S.W. were responsible for the experimental work. Y.L. was responsible for the growth of the SWCNTs. L.M.P. conceived the project and supervised the research work. All authors discussed the results and contributed to the preparation of the manuscript.

Corresponding author

Correspondence to Lian-Mao Peng.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 594 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yang, L., Wang, S., Zeng, Q. et al. Efficient photovoltage multiplication in carbon nanotubes. Nature Photon 5, 672–676 (2011).

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