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CdTe Solar Cells: Processing Limits and Defect Chemistry Effects on Open Circuit Voltage

Published online by Cambridge University Press:  28 August 2013

Brian E. McCandless*
Affiliation:
Institute of Energy Conversion, 451 Wyoming Road, University of Delaware, Newark, DE 19716, U.S.A.
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Abstract

The role of CdTe solar cell processing on the defect chemistry that limits open circuit voltage (VOC) is addressed in the thermochemical processing regimes commonly encountered in present-generation CdTe devices. The highest VOC is 0.91 V for a bulk CdTe crystal with ITO which is only marginally higher than VOC = 0.86 V obtained for polycrystalline CdTe films with CdS. Both fall ∼0.4 V short of the VOC expected for CdTe, having band gap EG = 1.5 eV. The present >16% efficient superstrate CdTe cell uses a process based on high-temperature, T > 500°C, CdTe growth on CdS, coupled with optimized methods for incorporating oxygen, sulfur, copper, and chloride species in the CdTe film. Pushing cell conversion efficiencies beyond 20% will require increasing VOC beyond 1V. However the present pathway of processing optimization will likely yield VOC and efficiency converging on 0.9 V and <20%, respectively.

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Articles
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Gloeckler, M., Zankin, I., Zhao, Z., Presented at 39th IEEE PVSC (May, 2013).Google Scholar
Shockley, W. and Queisser, H. J., J. Appl. Phys. 32 (1961) 510519.CrossRefGoogle Scholar
Nakazawa, T., Takamizawa, K., Ito, K., Appl. Phys. Lett. 50(5) (1987) 279280.CrossRefGoogle Scholar
For a description of CdTe and CdS cell fabrication methods, see: McCandless, B. E. and Sites, J. R., “Cadmium Telluride Solar Cells”, Chapter 14 in Handbook of Photovoltaic Science and Engineering, Wiley (2011).Google Scholar
McCandless, B. E., Engelmann, M., Birkmire, R. W., J. Appl. Phys. 89(2) (2001) 988994.CrossRefGoogle Scholar
McCandless, B. E. and Sites, J. R., “Cadmium Telluride Solar Cells”, Chapter 14 in Handbook of Photovoltaic Science and Engineering, Wiley (2011) p.619.Google Scholar
Hegedus, S. S. and Shafarman, W. N., Progress in Photovoltaics: Research and Applications, McCandless, B. E., Editor, 12(2-3) (2004) 155176.Google Scholar
Rockett, A., University of Illinois Urbana-Champaign (2011).Google Scholar
Pan, J., Doctoral Dissertation, Colorado State University (2007).Google Scholar
Kanevce, A., Kuciauskas, D., Gessert, T. A., Levi, D. H., Albin, D. S., Conf. Rec. 40th IEEE PVSC (2012).Google Scholar
Barnard, E. S., et al. ., Scientific Reports, 3:2098 (28 June 2013).CrossRefGoogle Scholar
Ahrenkiel, R., Levi, D., Arch, J., Solar Energy Materials and Solar Cells, 41/42 (1996) 171181.CrossRefGoogle Scholar
Wei, S.-H., Mtg. Record, National CdTe R&D Team Meeting (2001), also this conference, paper C13.01.Google Scholar
McCandless, B. E. and Buchanan, W. A., Conf. Rec. 33rd IEEE PVSC (2008).Google Scholar
Plotnikov, V., Kwon, D., Wieland, K., Compaan, A., Conf. Rec. 34th IEEE PVSC (2009) 14351438.Google Scholar
Marfaing, Y., Thin Solid films, 387 (2001) 123128.CrossRefGoogle Scholar
McCandless, B. E., unpublished analysis of Seebeck voltage on treated CdTe films on glass.Google Scholar
Hanket, G.M., McCandless, B.E., Buchanan, W.A., Fields, S., Birkmire, R.W., J. Vac. Sci.. and Technology A., 24(5), (2006) 16951702.CrossRefGoogle Scholar
Seymour, F. and Beach, J., National CdTe Team Collaboration (2006) unpublished.Google Scholar
Cohen, D., University of Oregon, private communication, 22 September 2012.Google Scholar
Aven and Prener (Editors), Physics and Chemistry of II-VI Compounds, Wiley (1967) p.234.Google Scholar