Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-26T02:58:06.539Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of Cu Deficiency on CuIn1-xGaxSe2 and High-efficiency Photovoltaic Solar Cells

Published online by Cambridge University Press:  01 February 2011

Sung-Ho Han ,
Falah S. Hasoon ,
Joel W. Pankow ,
Allen M. Hermann  and
Dean H. Levi
Sung-Ho Han
Affiliation:
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393, U.S.A. Department of Physics, University of Colorado, 2000 Colorado Avenue, Boulder, CO 80303-0390, U.S.A.
Falah S. Hasoon
Affiliation:
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393, U.S.A.
Joel W. Pankow
Affiliation:
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393, U.S.A.
Allen M. Hermann
Affiliation:
Department of Physics, University of Colorado, 2000 Colorado Avenue, Boulder, CO 80303-0390, U.S.A.
Dean H. Levi
Affiliation:
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393, U.S.A.
Get access

Abstract

We report the results of our studies on the optical and electronic structure of a wide range of polycrystalline thin-film CuIn1-xGaxSe2 (CIGS) alloys. The composition range includes CIS and nearly stoichiometric (slightly Cu-poor) (24.3±0.3 at.% Cu) CIGS with x values located around the value that has the best efficiency (x ∼ 0.28). Relative to nearly stoichiometric CIS and CIGS, we find a reduction in the absorption strength in the spectral range 1-3 eV. This reduction can be explained in terms of the predominance of Cu 3d and Se 4p states at the valence band maximum (VBM). In addition, Cu-poor CIS and CIGS materials show an increase in bandgap because the p-d repulsive interaction in Cu-poor CIGS is less than that in nearly stoichiometric CIGS. High efficiency is discussed in terms of optical properties.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 865: Symposium F – Thin-Film Compound Semiconductor Photovoltaics , 2005 , F1.3
Copyright
Copyright © Materials Research Society 2005

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

1 Ramanathan, K., Contreras, M. A., Perkins, C. L., Asher, S., Hasoon, F. S., Keane, J., Young, D., Romero, M., Metzger, W., Noufi, R., Ward, J., and Duda, A., Prog. Photovolt. Res. Appl. 11, 225 (2003).Google Scholar
2 Contreras, M. A. et al. , 1994 IEEE 1st WCPEC Conf. Record of 24th IEEE PVSC, pp. 68–75 (1995).Google Scholar
3 Persson, C. and Zunger, A., Phys. Rev. Lett. 91, 266401 (2003).Google Scholar
4 Alonso, M. I., Wakita, K., Pascual, J., Garriga, M., and Yamamoto, N., Phys. Rev. B 63, 075203 (2001).Google Scholar
5 Alonso, M. I., Garriga, M., Durante Rincön, C. A., Hernández, E., and León, M., Appl. Phys. A: Mater. Sci. Process. 74, 659 (2002).Google Scholar
6 A. Azzam, R. M. and Bashara, N. M., Ellipsometry and Polarized Light, 1st ed. (North-Holland, Amsterdam, 1977) p. 270–283.Google Scholar
7 Lautenschlager, P., Garriga, M., Logothetidis, S., and Cardona, M., Phys. Rev. B 35, 9174 (1987).Google Scholar
8 Savitzky, A. and Golay, M. J. E., Anal. Chem. 36, 1627 (1964); J. Steinier, Y. Termonia, and J. Deltour, Anal. Chem. 44, 1906 (1972).Google Scholar
9 Han, S.H., Hermann, A. M., Hasoon, F. S., Al-Thani, H. A., and Levi, D. H., Appl. Phys. Lett. 85, 576 (2004).Google Scholar
10 Zhang, S. B., Wei, S.H., and Zunger, A., Phys. Rev. B 57, 9642 (1998).Google Scholar
11 Ramanathan, K. et al. , Prog. Photovolt. Res. Appl. 11, 225 (2003); C. H. Champness, Proceedings of the 29th IEEE Conference (IEEE, Piscataway, 2002), p. 732.Google Scholar