Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-19T06:43:29.587Z Has data issue: false hasContentIssue false

Electronically stimulated degradation of silicon solar cells

Published online by Cambridge University Press:  01 January 2006

J. Schmidt*
Affiliation:
Institut für Solarenergieforschung Hameln/Emmerthal (ISFH), D-31860 Emmerthal, Germany
K. Bothe
Affiliation:
Institut für Solarenergieforschung Hameln/Emmerthal (ISFH), D-31860 Emmerthal, Germany
D. Macdonald
Affiliation:
Department of Engineering, Australian National University, Canberra ACT 0200, Australia
J. Adey
Affiliation:
School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
R. Jones
Affiliation:
School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
D.W. Palmer
Affiliation:
School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
*
a)Address all correspondence to this author.e-mail: [email protected] This paper was selected as the Outstanding Meeting Paper for the 2005 MRS Spring Meeting Symposium E Proceedings, Vol. 864.
Get access

Abstract

Carrier lifetime degradation in crystalline silicon solar cells under illumination with white light is a frequently observed phenomenon. Two main causes of such degradation effects have been identified in the past, both of them being electronically driven and both related to the most common acceptor element, boron, in silicon: (i) the dissociation of iron-boron pairs and (ii) the formation of recombination-active boron-oxygen complexes. While the first mechanism is particularly relevant in metal-contaminated solar-grade multicrystalline silicon materials, the latter process is important in monocrystalline Czochralski-grown silicon, rich in oxygen. This paper starts with a short review of the characteristic features of the two processes. We then briefly address the effect of iron-boron dissociation on solar cell parameters. Regarding the boron-oxygen-related degradation, the current status of the physical understanding of the defect formation process and the defect structure are presented. Finally, we discuss different strategies for effectively avoiding the degradation.

Type
Outstanding Meeting Papers: Review
Copyright
Copyright © Materials Research Society 2006

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.Macdonald, D.H., Geerlings, L.J. and Azzizi, A.: Iron detection in crystalline silicon by carrier lifetime measurements for arbitrary injection and doping. J. Appl. Phys. 95, 1021 (2004).CrossRefGoogle Scholar
2.Fischer, H. and Pschunder, W.: Investigation of photon and thermal induced changes in silicon solar cells. In Proc. 10th IEEE Photovolt. Spec. Conf. (IEEE, New York, 1973), p. 404.Google Scholar
3.Schmidt, J., Aberle, A.G., and Hezel, R.: Investigation of carrier lifetime instabilities in Cz-grown silicon. In Proc. 26th IEEE Photovolt. Spec. Conf. (IEEE, New York, 1997), p. 13.Google Scholar
4.Glunz, S.W., Rein, S., Warta, W., Knobloch, J., and Wettling, W.: On the degradation of Cz–Silicon solar cells, in Proc. 2nd World Conf. Photovolt. Solar Energy Conv. (EC, Ispra, Italy 1998), p. 1343.Google Scholar
5.Bothe, K., Hezel, R. and Schmidt, J.: Recombination-enhanced formation of the metastable boron-oxygen complex in crystalline silicon. Appl. Phys. Lett. 83, 1125 (2003).CrossRefGoogle Scholar
6.Istratov, A.A., Hieslmair, H. and Weber, E.R.: Iron and its complexes in silicon. Appl. Phys. A 69, 13 (1999).CrossRefGoogle Scholar
7.Kimerling, L.C. and Benton, J.L.: Electronically controlled reactions of interstitial iron in silicon. Physica B 116, 297 (1983).CrossRefGoogle Scholar
8.Macdonald, D. and Cuevas, A.: Reduced fill factors in multicrystalline silicon solar cells due to injection-level dependent bulk recombination lifetimes. Prog. Photovolt. 8, 363 (2000).3.0.CO;2-Y>CrossRefGoogle Scholar
9.Schmidt, J.: Effect of dissociation of iron-boron pairs in crystalline silicon on solar cell properties. Prog. Photovolt. 13, 325 (2005).CrossRefGoogle Scholar
10.Schmidt, J. and Cuevas, A.: Electronic properties of light-induced recombination centers in boron-doped Czochralski silicon. J. Appl. Phys. 86, 3175 (1999).CrossRefGoogle Scholar
11.Kimerling, L.C., Asom, M.T., Benton, J.L., Drevinsky, P.J. and Caefer, C.E.: Interstitial defect reactions in silicon. Mater. Sci. Forum 38–41, 141 (1989).Google Scholar
12.Rein, S. and Glunz, S.: Electronic properties of the metastable defect in boron-doped Czochralski silicon: Unambiguous determination by advanced lifetime spectroscopy. Appl. Phys. Lett. 82, 1054 (2003).CrossRefGoogle Scholar
13.Bothe, K., Hezel, R. and Schmidt, J.: Understanding and reducing the boron-oxygen-related performance degradation in Czochralski silicon solar cells. Solid State Phenomena 95–96, 223 (2004).Google Scholar
14.Rein, S., Rehrl, T., Warta, W., Glunz, S.W., and Willeke, G.: Electrical and thermal properties of the metastable defect in boron-doped Czochralski silicon, in Proc. 17th European Photovolt. Solar Energy Conf. (WIP-ETA, Munich, Germany, 2001), p. 1555.Google Scholar
15.Schmidt, J. and Bothe, K.: Structure and transformation of the metastable boron- and oxygen-related defect center in crystalline silicon. Phys. Rev. B 69, 024107 (2004).CrossRefGoogle Scholar
16.Rein, S., Glunz, S.W., and Willeke, G.: Metastable defect in Cz–Si: Electrical properties and quantitative correlation with different impurities, in Proc. 3rd World Conf. Photovolt. Solar Energy Conv. (2003), p. 2899.Google Scholar
17.Schmidt, J., Bothe, K., and Hezel, R.: Formation and annihilation of the metastable defect in boron-doped Czochralski silicon, in Proc. 29th IEEE Photovolt. Spec. Conf. (IEEE, New York, 2002), p. 178.Google Scholar
18.Murin, L.I., Hallberg, T., Markevich, V.P. and Lindström, J.L.: Experimental evidence of the oxygen dimer in silicon. Phys. Rev. Lett. 80, 93 (1998).CrossRefGoogle Scholar
19.Ewels, C.P., Density functional modelling of point defects in semiconductors. Ph.D. Thesis, University of Exeter, U.K. (1997).Google Scholar
20.Adey, J., Jones, R., Palmer, D.W., Briddon, P.R. and Öberg, S.: Degradation of boron-doped Czochralski silicon solar cells. Phys. Rev. Lett. 93, 055504 (2004).CrossRefGoogle ScholarPubMed
21.Lee, Y.J., von Boehm, J., Pesola, M. and Nieminen, R.M.: Aggregation kinetics of thermal double donors in silicon. Phys. Rev. Lett. 86, 3060 (2001).CrossRefGoogle ScholarPubMed
22.Glunz, S., Rein, S., Knobloch, J., Wettling, W. and Abe, T.: Comparison of boron- and gallium-doped p-type Czochralski silicon for photovoltaic application. Prog. Photovolt. 7, 463 (1999).3.0.CO;2-H>CrossRefGoogle Scholar
23.Glunz, S., Rein, S., Lee, J. and Warta, W.: Minority carrier lifetime degradation in boron-doped Czochralski silicon. J. Appl. Phys. 90, 2397 (2001).CrossRefGoogle Scholar
24.Metz, A., Abe, T., and Hezel, R.: Gallium-doped Czochralski grown silicon: A novel promising material for the PV industry. Proc. 16th European Photovolt. Solar Energy Conf. (James & James, London, U.K., 2000), p. 1189.Google Scholar
25.Zhao, J., Wang, A., and Green, M.: High efficiency PERT cells on a variety of single crystalline silicon substrates, in Proc. 16th European Photovolt. Solar Energy Conf. (James & James, London, U.K., 2000), p. 1100.Google Scholar
26.Zhao, J., Wang, A. and Green, M.: Performance degradation in CZ(B) cells and improved stability high efficiency PERT and PERL silicon cells on a variety of SEH MCZ(B), FZ(B) and CZ(Ga) substrates. Prog. Photovolt. 8, 549 (2000).3.0.CO;2-Y>CrossRefGoogle Scholar
27.Glunz, S., Rein, S., Warta, W., Knobloch, J. and Wettling, W.: Degradation of carrier lifetime in Cz silicon solar cells. Sol. Energy Mater. Sol. Cells 65, 219 (2001).CrossRefGoogle Scholar
28.Bothe, K., Schmidt, J., and Hezel, R.: Effective reduction of the metastable defect concentration in boron-doped Czochralski silicon for solar cells, in Proc. 29th IEEE Photovolt. Spec. Conf. (IEEE, New York, 2002), p. 194.Google Scholar
29.Nagel, H., Merkle, A., Metz, A., and Hezel, R.: Permanent reduction of excess-carrier-induced recombination centers in solar grade Czochralski silicon by a short yet effective anneal, in Proc. 16th European Photovolt. Solar Energy Conf. (James & James, London, U.K., 2000), p. 1197.Google Scholar
30.Lee, J., Peters, S., Rein, S. and Glunz, S.: Improvement of charge minority-carrier lifetime in p(boron)-type Czochralski silicon by rapid thermal annealing. Prog. Photovolt. 9, 417 (2001).Google Scholar
31.Schmidt, J. and Cuevas, A.: Progress in understanding and reducing the light degradation of Cz silicon solar cells, in Proc. 16th European Photovolt. Solar Energy Conf. (James & James, London, U.K., 2000) p. 1193.Google Scholar
32.Münzer, K., Holdermann, K., Schlosser, R. and Sterk, S.: Thin monocrystalline silicon solar cells. IEEE Trans. Electron Dev. 46, 2055 (1999).CrossRefGoogle Scholar
33.Glunz, S., Dicker, J., Lee, J., Preu, R., Rein, S., Schneiderlöchner, E., Sölter, J., Warta, W., and Willeke, G.: High-efficiency cell structures for medium-quality silicon, in Proc. 17th European Photovolt. Solar Energy Conf. (WIP-ETA, Munich, Germany, 2001), p. 1287.Google Scholar