Skip to main content Accessibility help
×
Home

High-Rate Plasma Process for Microcrystalline Silicon: Over 9% Efficiency Single Junction Solar Cells

  • Takuya Matsui (a1), Akihisa Matsuda (a1) and Michio Kondo (a1)

Abstract

This paper presents microcrystalline silicon (μ c-Si:H) p-i-n (superstrate-type) solar cells fabricated by 100 MHz plasma-enhanced chemical vapor deposition (PECVD) at i-layer deposition rates of >2 nm/s. Under high-rate conditions, in particular, the deposition pressure is found to play a dominant role in determining short circuit current (Jsc) of solar cell. With anincrease in deposition pressure from 3 to 7-9 Torr, Jsc increases by more than 50% due to a significant improvement in the long wavelength (>600 nm) responses, which essentially leads to high efficiency (∼8%) solar cells in the 2-3 nm/s deposition rate range. Further progress in solar cell efficiency has been made by the improvement of TCO/p and p/i interfaces. As a result, efficiency reaches 9.13% (Jsc=23.7 mA/cm2,Voc=0.528 V,FF=0.73) with a 2.3μm-thick i-layer grown at 2.3 nm/s. Transmission electron microscopy and secondary-ion mass spectroscopy studies reveal that samples prepared at lower pressure (∼4 Torr) comprise many grain boundaries due to disordered grain growth, which induces an anomalous incorporation of atmospheric impurities (predominantly oxygen) after exposing sample to air. In contrast, the high-pressure process (<7 Torr) provides denser grain columns coalesced with [110]-oriented crystallites, which in turn inhibits impurities from penetrating deeper in the film. Based on above results, we propose that the less post-oxidation behavior associated with the denser microstructure of high-pressure-grown μc-Si:H is responsible for the excellent charge collection in p-i-n solar cells.

Copyright

References

Hide All
1. Meier, J., Dubail, S., Flückiger, R., Keppner, H. and Shah, A., Appl. Phys. Lett. 65, 860 (1994).
2. Yamamoto, K., IEEE Trans. Electron Devices 46, 2041 (1999).
3. Saito, K., Sano, M., Sakai, A., Hayashi, R. and Ogawa, K., Tech. Dig. 20th Int. PVSEC, Jeju, Korea (Kyung Hee Information Printing, Seoul, 2001). p. 429.
4. Nasuno, Y., Kondo, M. and Matsuda, A., Jpn. J. Appl. Phys. 41, 5912 (2002).
5. Vetterl, O., Carius, R., Houben, L., Scholten, C., Luysberg, M., Lambertz, A., Finger, F. and Wagner, H., Mater. Res. Soc. Symp. Proc. 609, A15.2.1 (2000).
6. Matsui, T., Muhida, R., Kawamura, T., Toyama, T., Okamoto, H., Yamazaki, T., Honda, S., Takakura, H. and Hamakawa, Y., Appl. Phys. Lett. 81, 4751(2002).
7. Klein, S., Finger, F., Carius, R., Rech, B., Houben, L., Luysberg, M. and Stutzmann, M., Mater. Res. Soc. Symp. Proc. 715, A26.2 (2002).
8. Matsuda, A., J. Non-Cryst. Solids 59/60, 767 (1983).
9. Kondo, M., Fukawa, M., Guo, L. and Matsuda, A., J. Non-Cryst. Solids 266–269 84 (2000).
10. Vetterl, O., Finger, F., Carius, R., Hapke, P., Houben, L., Kluth, O., Lambertz, A., Muck, A., Rech, B. and Wagner, H., Sol. Energy Mater. & Sol. Cells 62, 97 (2000).
11. Matsui, T., Kondo, M. and Matsuda, A., Jpn. J. Appl. Phys. 42 (2002) L901.
12. Finger, F., Kroll, U., Viret, V., Shah, A., Beyer, W., Tang, X.-M., Weber, J., Howling, A. and Hollenstein, Ch., J. Appl. Phys. 71, 5665 (1992).
13. Roschek, T., Repmann, T., Müller, J., Rech, B. and Wagner, H., J. Vac. Sci. & Technol. A 20, 492 (2002).
14. Matsui, T., Tsukiji, M., Saika, H., Toyama, T. and Okamoto, H., Jpn. J. Appl. Phys. 41 (2002) 20.
15. Matsui, T., Kondo, M. and Matsuda, A., Proc of 3rd WCPEC Osaka, Japan, (2003) p.1548.
16. Werner, J. H., Dassow, R., Köhler, T. J. and Bergmann, R. B., Thin Solid Films 383 (2001) 95.
17. Newman, R. C. and Jones, R., in Oxygen in Silicon, edited by Shimura, F. (Academic, San Diego, 1994), Vol. 42, p. 289.
18. Veprek, S., Iqbal, Z., Kühne, R. O., Capezzuto, P., Sarott, F-A. and Gimzewski, J. K., J. Phys. C: Solid State Phys. 16, 6241 (1983).
19. Lucovsky, G., Wang, C., Williams, M. J., Chen, Y. L. and Maher, D. M., Mater. Res. Soc. Symp. Proc. 283, 443 (1993).
20. Torres, P., Meier, J., Flückiger, R., Kroll, U., Selvan, J. A. Anna, Keppner, H., Shah, A., Littlewood, S. D., Kelly, I. E. and Giannoulès, P., Appl. Phys. Lett. 69, 1373 (1996).
21. Nasuno, Y., Kondo, M. and Matsuda, A., Appl. Phys. Lett. 78, 2330 (2001).

High-Rate Plasma Process for Microcrystalline Silicon: Over 9% Efficiency Single Junction Solar Cells

  • Takuya Matsui (a1), Akihisa Matsuda (a1) and Michio Kondo (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed