Characterisation of the physico-chemical properties of surface-treated indium tin oxide anodes for organic light-emitting diodes

Abstract

We studied the surface properties of indium-tin oxide (ITO) modified by wet (aquaregia, ultrasonication, RCA) and dry (oxygen- and argon-plasma) treatments. The surface modification was investigated by surface energy, surface morphology, sheet resistance, carrier concentration, carrier mobility, and workfunction measurements. We report that the studied oxygen-plasma treatment induces: the highest surface energy with the highest polarity, the smoothest surface, the highest carrier density but the lowest mobility, the lowest sheet resistance, and the highest workfunction (stable in air). Polymer light-emitting diodes fabricated with the oxygen plasma treated substrates give the best performance in terms of electroluminescence efficiency and device lifetime. This is attributed to a favorable surface modification of ITO anodes by oxygen-plasma.

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

References

  1. 1.

    S. Karg, J. C. Scott, J. R. Salem, and M. Angelopoulos, Synth. Met. 80, 111–117 (1996).

    CAS  Article  Google Scholar 

  2. 2.

    A. Berntsen, Y. Croonen, R. Cuijpers, B. Habets, C. Liedenbaum, H. Schoo, R. J. Visser, J. Vleggaar, and P.v. d. Weijer, The Proceedings of SPIE’s 42nd Annual Meeting, San Diego 3148, 264–271 (1997).

    CAS  Google Scholar 

  3. 3.

    S. A. Carter, M. Angelopoulos, S. Karg, P. J. Brock, and J. C. Scott, Appl. Phys. Lett. 70, 2067–2069 (1997).

    CAS  Article  Google Scholar 

  4. 4.

    J. C. Carter, I. Grizzi, S. K. Heeks, D. J. Lacey, S. G. Latham, P. G. May, O. R. Delospanos, K. Pichler, C. R. Towns, and H. F. Wittmann, Appl. Phys. Lett. 71, 34–36 (1997).

    CAS  Article  Google Scholar 

  5. 5.

    C. C. Wu, C. I. Wu, J. C. Sturm, and A. Kahn, Appl. Phys. Lett. 70, 1348–1350 (1997).

    CAS  Article  Google Scholar 

  6. 6.

    S. Fujita, T. Sakamoto, K. Ueda, K. Ohta, and S. Fujita, Jap. J. Appl. Phys. Part 1 - Regular Papers Short Notes & Rev. Papers 36, 350–353 (1997).

    CAS  Article  Google Scholar 

  7. 7.

    F. Li, H. Tang, J. Shinar, O. Resto, and S. Z. Weisz, Appl. Phys. Lett. 70, 2741–2743 (1997).

    CAS  Article  Google Scholar 

  8. 8.

    C. Y. Chang and S. M. Sze, ULSI Technology (McGraw-Hill, Singapore, 1996), pp60–62.

    Google Scholar 

  9. 9.

    S. Wu, Polymer Interface and Adhesion (Marcel Dekker Inc., New York, 1982), pp171–178.

    Google Scholar 

  10. 10.

    J. S. Kim, R. H. Friend, and F. Cacialli, Appl. Phys. Lett., in press.

  11. 11.

    J. S. Kim, F. Cacialli, A. Cola, G. Gigli, and R. Cingolani, submitted to Appl. Phys. Lett. (1999).

  12. 12.

    J. S. Kim, M. Granstrdm, R. H. Friend, N. Johansson, W. R. Salaneck, R. Daik, W. J. Feast, and F. Cacialli, J. Appl. Phys. 84, 6859–6870 (1998).

    CAS  Article  Google Scholar 

  13. 13.

    P. A. Cox, The Electronic Structure and Chemistry of Solids (Oxford University Press, New York, 1987) pp230–232.

    Google Scholar 

  14. 14.

    T. Ishida, H. Kobayashi, and Y. Nakato, J. Appl. Phys. 73, 4344–4350 (1993).

    CAS  Article  Google Scholar 

  15. 15.

    J. S. Kim, P. K. H. Ho, R. H. Friend, G. W. Bao, S. F. Y. Li, and F. Cacialli, unpublished.

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to J. S. Kima.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kima, J.S., Granströma, M., Friend, R.H. et al. Characterisation of the physico-chemical properties of surface-treated indium tin oxide anodes for organic light-emitting diodes. MRS Online Proceedings Library 558, 427–432 (1999). https://doi.org/10.1557/PROC-558-427

Download citation