Hostname: page-component-76fb5796d-skm99 Total loading time: 0 Render date: 2024-04-26T02:49:22.562Z Has data issue: false hasContentIssue false
  • English
  • Français

High Efficiency Sputtered CdS/CdTe Cells without CdCl2 Activation

Published online by Cambridge University Press:  20 June 2011

N.R. Paudel ,
K.A. Wieland  and
A.D. Compaan
N.R. Paudel
Affiliation:
Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 USA
K.A. Wieland
Affiliation:
Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 USA
A.D. Compaan
Affiliation:
Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 USA
Get access

Abstract

Polycrystalline thin-film CdS/CdTe PV cells nearly always require “activation” with vapors containing chlorine and oxygen near 400 oC in order to realize the highest cell performance, even when growth occurs near 600 oC. In this study we have used film growth near 270 oC by magnetron sputtering in an oxygen-free ambient and have studied the effects of post-deposition heat treatments for 20 minutes at 400, 425 and 450 oC without CdCl2 in a dry air ambient. The heat treatments enhanced grain growth and produced re-crystallization of the CdTe film at all three temperatures, but 450 oC was required to reach the best electrical performance. Grain size increased from a couple of hundred nanometers to more than a micron as the preferred (111) growth orientation decreased. Efficiencies up to 11.6% were achieved with no CdCl2 compared to ~13% with activation at 387 oC in the presence of CdCl2 vapors. X-ray diffraction and quantum efficiency measurements show interdiffusion of CdS and CdTe at 450 oC comparable with a standard CdCl2 treatment at 387 oC. The results are discussed in terms of CdSTe alloy gradients and minority-carrier diffusion lengths.

Keywords

thin filmsputteringcrystal growth
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1323: Symposium C – Advanced Materials Processing for Scalable Solar-Cell Manufacturing , 2011 , mrss11-1323-c06-03
Copyright
Copyright © Materials Research Society 2011

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. Shao, M., Fischer, A., Grecu, D., Jayamaha, U., Bykov, E., Contreras-Puente, G., Bohn, R. G., and Compaan, A. D., Appl. Phys. Lett. 69, 3045 (1996).Google Scholar
2. Meyers, P. V., Liu, C. H., and Frey, T. J., U. S. Patent No. 4,873,198 (10 October 1989).Google Scholar
3. Wu, X., Keane, J. C., Dhere, R. G., DeHart, C., Albin, D. S., Duda, A., Gessert, T. A., Asher, S., Levi, D. H., and Sheldon, P., Proc. 17th EPVSEC, 995 (2001).Google Scholar
4. Gupta, A. and Compaan, A.D., Appl. Phys. Lett., 84, 684 (2004).Google Scholar
5. Enriquez, J. P. and Mathew, X., J. Mater. Sci.: Materials in Electronics, 16, 617 (2005).Google Scholar
6. McCandless, B. E. and Dobson, K. D., Solar Energy, 77, 839 (2004).Google Scholar
7. Vamsi Krishna, K. and Dutta, V., Thin Solid Films, 450, 255 (2004).Google Scholar
8. Ringel, S. A., Smith, A. W., MacDougal, M. H., and Rohatgi, A., J. Appl. Phys., 70, 881 (1991).Google Scholar
9. Kim, K.H., and Chun, J.S., Thin Solid Films, 141, 287 (1986).Google Scholar
10. Moutinho, H. R., Al-Jassim, M. M., Levi, D. H., Dippo, P. C., and Kazmerski, L. L., J. Vac. Sci. Technol. A 16, 1251 (1998).Google Scholar
11. Toyama, T., Matsune, K., Oda, H, Ohta, M and Okamoto, H, J. Phys. D: Appl. Phys. 39, 1537 (2006).Google Scholar
12. Taylor, A. and Sinclair, H., Proc. Phys. Soc. London 57, 126 (1945).Google Scholar
13. Nelson, J.B. and Riley, D.P., Proc. Phys. Soc. London 57, 160 (1945).Google Scholar