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.

Superconductivity in alkali-metal-doped picene


Efforts to identify and develop new superconducting materials continue apace, motivated by both fundamental science and the prospects for application. For example, several new superconducting material systems have been developed in the recent past, including calcium-intercalated graphite compounds1, boron-doped diamond2 and—most prominently—iron arsenides such as LaO1–xF x FeAs (ref. 3). In the case of organic superconductors, however, no new material system with a high superconducting transition temperature (Tc) has been discovered in the past decade. Here we report that intercalating an alkali metal into picene, a wide-bandgap semiconducting solid hydrocarbon, produces metallic behaviour and superconductivity. Solid potassium-intercalated picene (K x picene) shows Tc values of 7 K and 18 K, depending on the metal content. The drop of magnetization in K x picene solids at the transition temperature is sharp (<2 K), similar to the behaviour of Ca-intercalated graphite1. The Tc of 18 K is comparable to that of K-intercalated C60 (ref. 4). This discovery of superconductivity in K x picene shows that organic hydrocarbons are promising candidates for improved Tc values.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Figure 1: Molecular structure, crystal structure and physical appearance of picene.
Figure 2: Temperature dependence of M/H.
Figure 3: Superconducting phase diagrams.


  1. Emery, N. et al. Superconductivity of bulk CaC6 . Phys. Rev. Lett. 95, 087003 (2005)

    Article  ADS  CAS  Google Scholar 

  2. Ekimov, E. A. et al. Superconductivity in diamond. Nature 428, 542–545 (2004)

    Article  ADS  CAS  Google Scholar 

  3. Kamihara, Y., Watanabe, T., Hirano, M. & Hosono, H. Iron-based layered superconductor La[O1-xFx]FeAs (x = 0.05 – 0.12) with T c = 26 K. J. Am. Chem. Soc. 130, 3296–3297 (2008)

    Article  CAS  Google Scholar 

  4. Hebard, A. F. et al. Superconductivity at 18 K in potassium-doped C60 . Nature 350, 600–601 (1991)

    Article  ADS  CAS  Google Scholar 

  5. Tanigaki, K. et al. Superconductivity at 33 K in CsxRbyC60 . Nature 352, 222–223 (1991)

    Article  ADS  CAS  Google Scholar 

  6. Fleming, R. M. et al. Relation of structure and superconducting transition temperatures in A3C60 . Nature 352, 787–788 (1991)

    Article  ADS  CAS  Google Scholar 

  7. Palstra, T. T. M. et al. Superconductivity at 40 K in cesium doped C60 . Solid State Commun. 93, 327–330 (1995)

    Article  ADS  CAS  Google Scholar 

  8. Ganin, A. Y. et al. Bulk superconductivity at 38 K in a molecular system. Nature Mater. 7, 367–371 (2008)

    Article  ADS  CAS  Google Scholar 

  9. Takabayashi, Y. et al. The disorder-free non-BCS superconductor Cs3C60 emerges from an antiferromagnetic insulator parent state. Science 323, 1585–1590 (2009)

    Article  ADS  CAS  Google Scholar 

  10. Weller, T. E. et al. Superconductivity in the intercalated graphite compounds, C6Yb and C6Ca. Nature Phys. 1, 39–41 (2005)

    Article  ADS  CAS  Google Scholar 

  11. Hannay, N. B. et al. Superconductivity in graphitic compounds. Phys. Rev. Lett. 14, 225–226 (1965)

    Article  ADS  CAS  Google Scholar 

  12. Minakata, T. et al. Conducting thin films of pentacene doped with alkaline metals. J. Appl. Phys. 74, 1079–1082 (1993)

    Article  CAS  Google Scholar 

  13. Matsuo, Y., Sasaki, S. & Ikehata, S. Stage structure and electrical properties of rubidium-doped pentacene. Phys. Lett. A 321, 62–66 (2004)

    Article  ADS  CAS  Google Scholar 

  14. Kaneko, Y., Suzuki, T., Matsuo, Y. & Ikehata, S. Metallic electrical conduction in alkaline metal-doped pentacene. Synth. Met. 154, 177–180 (2005)

    Article  CAS  Google Scholar 

  15. Okamoto, H. et al. Air-assisted high-performance field-effect transistor with thin films of picene. J. Am. Chem. Soc. 130, 10470–10471 (2008)

    Article  CAS  Google Scholar 

  16. Kawasaki, N. et al. Trap states and transport characteristics in picene thin film field-effect transistor. Appl. Phys. Lett. 94, 043310 (2009)

    Article  ADS  Google Scholar 

  17. Kaji, Y. et al. High-performance C60 and picene thin film field-effect transistors with conducting polymer electrodes in bottom contact structure. Org. Electron. 10, 432–436 (2009)

    Article  CAS  Google Scholar 

  18. De, A., Ghosh, R., Roychowdhury, S. & Roychowdhury, P. Structural analysis of picene, C22H14 . Acta Crystallogr. C 41, 907–909 (1985)

    Article  Google Scholar 

  19. Schirber, J. E. et al. Pressure-temperature phase diagram, inverse isotope effect, and superconductivity in excess of 13 K in κ-(BEDT-TTF)2Cu[N(CN)2]Cl, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. Phys. Rev. B 44, 4666–4669 (1991)

    Article  ADS  CAS  Google Scholar 

  20. Hansson, A., Bohlin, J. & Stafstrom, S. Structural and electronic transitions in potassium-doped pentacene. Phys. Rev. B 73, 184114 (2006)

    Article  ADS  Google Scholar 

Download references


The X-ray diffraction patterns were measured with synchrotron radiation at KEK-PF (proposal no. 2007G612), Tsukuba, Japan. This work was supported in part by Grants-in-Aid 20045012 and 18340104 from MEXT, Japan.

Author Contributions R.M., Y.S., Y.Y. and H.M. contributed equally to the preparation of superconducting picene materials and to the performance of magnetic susceptibility measurements with the assistance of T.K. and Y.K.; H.O. and M.Y. synthesized high-quality picene; N.K. and Y.M. provided assistance with X-ray diffraction measurements; N.I. and A.F. provided discussions and suggestions for the overall project, and discussed the experimental data with T.K. and Y.K.; Y.K. was responsible for the overall project direction, planning and integration among different research units.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Yoshihiro Kubozono.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Information, Supplementary Figures S1-S7 with Legends and Supplementary References. (PDF 994 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Mitsuhashi, R., Suzuki, Y., Yamanari, Y. et al. Superconductivity in alkali-metal-doped picene. Nature 464, 76–79 (2010).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


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