Hostname: page-component-7479d7b7d-rvbq7 Total loading time: 0 Render date: 2024-07-11T07:21:52.082Z Has data issue: false hasContentIssue false
  • English
  • Français

Microcrystalline (Si,Ge):H Solar Cells

Published online by Cambridge University Press:  01 February 2011

Jianhua Zhu  and
Vikram L. Dalal
Jianhua Zhu
Affiliation:
Dept. of Electrical and Computer Engr. and Microelectronics Research Center Iowa State University, Ames, Iowa 50011, USA
Vikram L. Dalal
Affiliation:
Dept. of Electrical and Computer Engr. and Microelectronics Research Center Iowa State University, Ames, Iowa 50011, USA
Get access

Abstract

We report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 762: Symposium A – Amorphous and Nanocrystalline Silicon-Based Films – 2003 , 2003 , A7.6
Copyright
Copyright © Materials Research Society 2003

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. Nasuno, Y., Kondo, M. and Matsuda, A., Solar Energy Mater. And Solar Cells, 74, 497–503(2002).Google Scholar
2. Vetterl, O., Finger, F., Carius, R., Hapke, P., Houben, L., Kluth, O., Lambertz, A., Mück, A., Rech, B. and Wagner, H., Solar Energy Mater. And Solar Cells, 62, 97–108(2000).Google Scholar
3. Meier, J., Dubail, S., Golay, S., Kroll, U., Faÿ, S., Vallat-Sauvain, E., Feitknecht, L., Dubail, J. and Shah, A., Solar Energy Mater. And Solar Cells, 74, 457–467(2002).Google Scholar
4. Yamamoto, Kenji, Yoshimi, Masashi, Tawada, Yuko, Fukuda, Susumu, Sawada, Toru, Meguro, Tomomi, Takata, Hiroki, Suezaki, Takashi, Koi, Yohei, Hayashi, Katsuhiko, Solar Energy Mater. And Solar Cells, 74, 449–455 (2002).Google Scholar
5. Rech, B., Kluth, O., Repmann, T., Roschek, T., Springer, J., Müller, J., Finger, F., Stiebig, H. and Wagner, H., Solar Energy Mater. And Solar Cells, 74, 439–447(2002).Google Scholar
6. Dalal, V. L. and Erickson, K., Proc. Of 28th. IEEE Photovolt. Spec. Conf. (2000), p.792–795.Google Scholar
7. Erickson, K. and Dalal, V. L., Proc. of MRS, 507, 987 (1998).Google Scholar
8. Isomura, M., Nakahata, K., Shima, M., Taira, S., Wakisaka, K., Tanaka, M. and Kiyama, S., Solar Energy Mater. And Solar Cells, 74, 519–524 (2002).Google Scholar