Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-27T00:42:01.107Z Has data issue: false hasContentIssue false
  • English
  • Français

Role of Surfaces and Interfaces for the Electronic Properties of Conducting Oxides

Published online by Cambridge University Press:  21 March 2011

Andreas Klein
Andreas Klein*
Affiliation:
Institute of Materials Science, Darmstadt University of TechnologyPetersenstrasse 23, 64287 Darmstadt, Germany
Get access

Abstract

Transparent conductive oxides (TCOs) are generally considered as degenerate semiconductors doped intrinsically by oxygen vacancies and by intentionally added dopants. For some applications a high work function is required in addition to high conductivity and it is desired to tune both properties independently. To increase the work function, the distance between the Fermi energy and the vacuum level must increase, which can be realized either by electronic surface dipoles or by space charge layers. Photoelectron spectroscopy data of in-situ prepared samples clearly show that highly doped TCOs can show surface band bending of the order of 1 eV. It is further shown that the band alignment at heterointerfaces between TCOs and other materials, which are crucial for many devices, are also affected by such band bending. The origin of the band bending, which seems to be general to all TCOs, depends on TCO thin film and surface processing conditions. The implication of surface band bending on the electronic properties of thin films and interfaces are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 666: Symposium F – Transport and Microstructural Phenomena , 2001 , F1.10
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Hartnagel, H.L., Dawar, A.L., Jain, A.K., and Jagadish, C., Semiconducting Transparent Thin Films (Institute of Physics Publishing, Bristol, 1995).Google Scholar
2. Burstein, E., Physical Review 93, 632 (1954); T.S. Moss, Proc. Phys. Soc. London B67, 775 (1954).Google Scholar
3. Mönch, W., Semiconductor surfaces and interfaces (Springer Verlag, Heidelberg, 1993).Google Scholar
4. Klein, A., Appl. Phys. Lett. 77, 2009–2011 (2000).Google Scholar
5. Lang, O., Pettenkofer, C., Sanchez-Royo, J.F., Segura, A., Klein, A., and Jaegermann, W., J. Appl. Phys. 86, 5687 (1999).Google Scholar
6. Hamberg, I. and Granqvist, C.G., J. Appl. Phys. 60, R123 (1986).Google Scholar
7. Sugiyama, K., Ishii, H., Ouchi, Y., and Seki, K., J. Appl. Phys. 87, 295–298 (2000).Google Scholar
8. Jacobi, K., Myler, U., and Althainz, P., Phys. Rev. B41, 10721–10726 (1990).Google Scholar
9. Rhodin, T.N. and Gadzuk, J.W., in The Nature of the Surface Chemical Bond, edited by Rhodin, T.N. and Ertl, G. (North-Holland, Amsterdam, 1979), p. 113–273.Google Scholar
10. Klein, A., Henrion, O., Pettenkofer, C., Jaegermann, W., Ashkenasy, N., Mishori, B., and Shapira, Y., Proc. of the 14th European Photovoltaic Solar Energy Conference (H.S. Stephens & Associates, Bedford, 1997), p. 1705.Google Scholar
11. Korobov, V., Leibovitch, M., and Shapira, Y., J. Appl. Phys. 74, 3251 (1993).Google Scholar
12. Ishii, H., Sugiyama, K., Yoshimura, D., Ito, E., Ouchi, Y., and Seki, K., IEEE J. Sel. Topics Quantum Electr. 4, 24 (1998); S. T. Lee, Y. M. Wang, X. Y. Hou, and C. W. Tang, Appl. Phys. Lett. 74, 670-672 (1999); I. G. Hill and A. Kahn, J. Appl. Phys. 86, 2116-2122 (1999).Google Scholar
13. Henrich, V. E. and Cox, P. A., The Surface Science of Metal Oxides (Cambridge University Press, Cambridge, 1994).Google Scholar