Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-17T17:54:48.644Z Has data issue: false hasContentIssue false

The Mechanism of J-V “Roll-Over” in CdS/CdTe Devices

Published online by Cambridge University Press:  01 February 2011

Jie Zhou
Affiliation:
Jie_zhou@nrel.gov, National Renewabel Energy Lab, Electronic Materials and Device Division, 1617 Cole Blvd, Golden, CO, 80401, United States
Xuanzhi Wu
Affiliation:
xuanzhi_wu@nrel.gov, National Renewable Energy Lab, 1617 Cole Blvd, Golden, CO, 80401, United States
Yanfa Yan
Affiliation:
yanfa_yan@nrel.gov, National Renewable Energy Lab, 1617 Cole Blvd, Golden, CO, 80401, United States
Sally Asher
Affiliation:
sally_asher@nrel.gov, National Renewable Energy Lab, 1617 Cole Blvd, Golden, CO, 80401, United States
Juarez Da Silva
Affiliation:
juarez_DaSilva@nrel.gov, National Renewable Energy Lab, 1617 Cole Blvd, Golden, CO, 80401, United States
Suhuai Wei
Affiliation:
suhuai_wei@nrel.gov, National Renewable Energy Lab, 1617 Cole Blvd, Golden, CO, 80401, United States
Lothar Weinhardt
Affiliation:
weinhard@unlv.nevada.edu, University of Nevada, Las Vegas, Department of Chemistry, Las Vegas, NV, 89154, United States
Marcus Bar
Affiliation:
baerm2@unlv.nevada.edu, University of Nevada, Las Vegas, Department of Chemistry, Las Vegas, NV, 89154, United States
Clemens Heske
Affiliation:
heske@unlv.nevada.edu, University of Nevada, Las Vegas, Department of Chemistry, Las Vegas, NV, 89154, United States
Get access

Abstract

The “roll-over” phenomenon in current-voltage (J-V) curves of CdS/CdTe devices is recognized as a result of the formation of a higher back barrier. When Cu has not been intentionally added to the back contact, roll-over is understandable. However, the mechanism was unclear for forming J-V roll-over in a CdTe cell with a back contact containing Cu. We did extensive characterizations, including XRD, XPS, SIMS, TEM, and EDS, and “recontact” experiments to understand this phenomenon. The results show that the roll-over comes from the formation of Cu-related oxides at the back side of the device during processing, rather than the diffusion of Cu to the front side of the device. Discussions related to the J-V roll-over mechanisms will also be presented.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

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. Stollwerck, G., and Sites, J., Proc. of 13th European PVSEC (Nice, France, 1995) pp. 2020.Google Scholar
2. Gessert, T. A., Mason, A. R., Sheldon, P., Swartzlander, A. B., Niles, D., and Coutts, T. J., J. Vac. Sci. Technol. A 14(3), 806812 (1996).Google Scholar
3. Fritsche, J., Kraft, D., ThiBen, A., Mayer, T., Klein, A., and Jaegermann, W., Thin Solid Films 403-404, 252256 (2002).Google Scholar
4. Niles, D. W., Li, X., and Sheldon, P., J. Appl. Phys. 77 (9), 44894493 (1995).Google Scholar
5. Wu, X., Zhou, J., Duda, A., Yan, Y., Teeter, G., Asher, S., Metzger, W. K., Demtsu, S., Wei, Su-Huai, and Noufi, R., Thin Solid Films (2007) (in press).Google Scholar
6. Kubaschewski, O. and Alcock, C. B., Metallurgical Thermochemistry, 5th edition (Pergamon Press, 1979).Google Scholar
7. Mills, K. C., Thermodynamic Data for Inorganic Sulphides, Selenides and Tellurides, (Redwood Press Limited, 1974).Google Scholar
8. Werthen, J. G., Haring, J.-P., and Bube, R. H., J. Appl. Phys. 54(2), 11591161 (1983).Google Scholar
9. Stirn, R. J., and Yeh, Y. C. M., Appl. Phys. Lett. 27(2), 9598 (1975).Google Scholar
10. Chu, T. L., and Chu, S. S., Ang, S. T., J. Appl. Phys. 58(8), 32063210 (1985).Google Scholar
11. Childs, R., Fortuna, J., Geneczko, J., and Fonash, S. J., Proc. of 12th IEEE PVSC (1976) pp. 862.Google Scholar
12. Dobson, K. D., Visoly-Fisher, I., Hodes, G., and Cahen, D., Sol. Energy Mater. Sol. Cells 62, 295325 (2000).Google Scholar
13. Romeo, N., Bosio, A., Canevari, V., Terheggen, M., and Roca, L. V., Thin Solid Films 431-432, 364368 (2003).Google Scholar