Skip to main content

Thank you for visiting nature.com. 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.

  • Letter
  • Published:

Direct imaging of carrier motion in organic transistors by optical second-harmonic generation

Nature Photonics volume 1, pages 581–584 (2007)Cite this article

Abstract

Interest in the dynamic behaviour of carriers in organic materials is motivated by possible applications that include organic thin-film transistors, organic electro-luminescent devices and organic photoconductors. It can also provide an insight into the modelling of carrier transport and trapping in organic semiconductors and insulators. Here, we use an advanced second-harmonic generation technique to probe and visualize real carrier motion in organic materials. This is a time-resolved microscopic optical second-harmonic generation technique that allows direct and selective probing of dynamic carrier motion in organic materials. Experiments making use of this technique and using pentacene field-effect transistors have revealed dynamic changes of second-harmonic-generation intensity profiles arising from pentacene. Carrier velocity in organic solids is thus determined from the visualized carrier motion. We anticipate that this direct visualization technique will find wide application in the illustration of space-charge field formation in organic and inorganic materials, including biomaterials and polymers.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Experimental configurations and results of the TRM-SHG measurement.
Figure 2: Calculated in-plane electric-field distribution and the second-harmonic profile assuming the distribution of carrier density in the channel.
Figure 3: Relationship between the position of the head of the carrier sheet in the OFET channel and delay time.

Similar content being viewed by others

References

  1. Sessler, G. M. Electrets (Springer, Berlin, 1980).

    Book  Google Scholar 

  2. Meier, H. Organic Semiconductors: Dark- and Photoconductivity of Organic Solids (Chemie, Weinheim, 1974).

    Google Scholar 

  3. Kepler, R. G. Charge carrier production and mobility in anthracene crystals. Phys. Rev. 119, 1226–1229 (1960).

    Article  ADS  Google Scholar 

  4. Iwamoto, M., Majima, Y., Naruse, H., Noguchi, T. & Fuwa, H. Generation of Maxwell displacement current across an azobenzene monolayer by photoisomerization. Nature 353, 645–647 (1991).

    Article  ADS  Google Scholar 

  5. Spear, W. E. Drift mobility techniques for the study of electrical transport properties in insulating solids. J. Noncryst. Solid 1, 197–214 (1969).

    Article  ADS  Google Scholar 

  6. Kitamura, M., Imada, T., Kako, S. & Arakawa, Y. Time-of-flight measurement of lateral carrier mobility in organic thin films. Jpn J. Appl. Phys. 43, 2326–2329 (2004).

    Article  ADS  Google Scholar 

  7. Laurenceau, P., Dreyfus, G. & Lewiner, J. New principle for the determination of potential distributions in dielectrics. Phys. Rev. Lett. 38, 46–49 (1977).

    Article  ADS  Google Scholar 

  8. Alquie, C., Dreyfus, G. & Lewiner, J. Stress-wave probing of electric field distributions in dielectrics. Phys. Rev. Lett. 47, 1483–1487 (1981).

    Article  ADS  Google Scholar 

  9. Maeno, T., Futami, T., Kushibe, H., Takeda, T. & Cooke, C. M. Measurement of spatial charge distribution in thick dielectrics using the pulsed electroacoustic method. IEEE Trans. Electr. Insul. 23, 433–439 (1988).

    Article  Google Scholar 

  10. Sessler, G. M., West, G. E. & Gerhard, G. High-resolution laser-pulse methods for measuring charge distribution in dielectrics. Phys. Rev. Lett. 48, 563–566 (1982).

    Article  ADS  Google Scholar 

  11. Manaka, T., Li, C. Q., Cheng, X. M. & Iwamoto, M. Spectroscopic consideration of the surface potential built across phthalocyanine thin films on a metal electrode. J. Chem. Phys. 120, 7725–7732 (2004).

    Article  ADS  Google Scholar 

  12. Manaka, T., Lim, E., Tamura, R. & Iwamoto, M. Modulation in optical second harmonic generation signal from channel of pentacene field effect transistors during device operation. Appl. Phys. Lett. 87, 222107 (2005).

    Article  ADS  Google Scholar 

  13. Manaka, T., Lim, E., Tamura, R., Yamada, D. & Iwamoto, M. Probing of the electric field distribution in organic field effect transistor channel by microscopic second-harmonic generation. Appl. Phys. Lett. 89, 072113 (2006).

    Article  ADS  Google Scholar 

  14. Lim, E., Manaka, T. & Iwamoto, M. Analysis of carrier injection into a pentacene field effect transistor by optical second harmonic generation measurements. J. Appl. Phys. 101, 024515 (2007).

    Article  ADS  Google Scholar 

  15. Manaka, T., Kohn, H., Ohshima, Y., Lim, E. & Iwamoto, M. Direct observation of trapped carriers in polydiacetylene field effect transistor by optical second harmonic generation. Appl. Phys. Lett. 90, 171119 (2007).

    Article  ADS  Google Scholar 

  16. Sze, S. M. Physics of Semiconductor Devices 2nd edn Section 8.2.2 (John Wiley & Sons, New York, 1981).

    Google Scholar 

  17. Kiguchi, M. et al. Accumulation and depletion layer thicknesses in organic field effect transistors. Jpn J. Appl. Phys. 42, L1408–1410 (2003).

    Article  ADS  Google Scholar 

  18. Lim, E., Manaka, T., Tamura, R. & Iwamoto, M. Maxwell–Wagner model analysis for the capacitance– voltage characteristics of pentacene field effect transistor. Jpn J. Appl. Phys. 45, 3712–3716 (2006).

    Article  ADS  Google Scholar 

  19. Scher, H. & Montroll, E. W. Anomalous transit-time dispersion in amorphous solids. Phys. Rev. B 12, 2455–2477 (1975).

    Article  ADS  Google Scholar 

  20. Bassler, H. Charge transport in disordered organic photoconductors. Phys. Status Solidi B 175, 15–56 (1993).

    Article  ADS  Google Scholar 

  21. Borsemberger, P. M., Magin, E. H., van der Auweraer, M. & De Schryver, F. C. The role of disorder on charge transport in molecularly doped polymers and related material. Phys. Status Solidi A 140, 9–47 (1993).

    Article  ADS  Google Scholar 

  22. Tamura, R., Lim, E., Manaka, T. & Iwamoto, M. Analysis of pentacene field effect transistor as a Maxwell–Wagner effect element. J. Appl. Phys. 100, 114515 (2006).

    Article  ADS  Google Scholar 

  23. Koehler, M. & Biaggio, I. Space-charge and trap-filling effects in organic thin film field-effect transistors. Phys. Rev. B 70, 045314 (2004).

    Article  ADS  Google Scholar 

  24. Ye, H., Abu-Akeel, A., Huang, J., Katz, H. E. & Gracias, D. H. Probing organic field effect transistors in-situ during operation using SFG. J. Am. Chem. Soc. 128, 6528–6529 (2006).

    Article  Google Scholar 

  25. Furukawa, Y., Yamamoto, J., Cho, D. C. & Mori, T. Voltage-induced infrared spectra from polymer field-effect transistors. Macromol. Symp. 205, 9–17 (2004).

    Article  Google Scholar 

  26. Manaka, T., Suzue, Y. & Iwamoto M. Investigation of the electrostatic phenomena at pentacene/metal interface by second-harmonic generation. Jpn J. Appl. Phys. 44, 2818–2822 (2005).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We acknowledge financial support by Grant-in-Aid for Young Scientist (A) (18686029) and Grant-in-Aid for Scientific Research (A) (19206034) from Ministry of Education, Culture, Sports, Science and Technology (MEXT).

Author information

Authors and Affiliations

  1. Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8552, Japan

    Takaaki Manaka, Eunju Lim, Ryousuke Tamura & Mitsumasa Iwamoto

Authors
  1. Takaaki Manaka
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Eunju Lim
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ryousuke Tamura
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Mitsumasa Iwamoto
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

T.M. planned the project and performed the experiment. E.L. and R.T. prepared the OFET samples. M.I. also planned the project.

Corresponding authors

Correspondence to Takaaki Manaka or Mitsumasa Iwamoto.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Manaka, T., Lim, E., Tamura, R. et al. Direct imaging of carrier motion in organic transistors by optical second-harmonic generation. Nature Photon 1, 581–584 (2007). https://doi.org/10.1038/nphoton.2007.172

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphoton.2007.172

This article is cited by

Search

Advanced search

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