Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-18T12:17:20.775Z Has data issue: false hasContentIssue false

Understanding of Passivation Mechanism in Heterojunction c-Si Solar Cells

Published online by Cambridge University Press:  01 February 2011

Michio Kondo
Affiliation:
[email protected], AIST, RCPV, Umezono, Tsukuba, 305-8568, Japan
Stefaan De Wolf
Affiliation:
[email protected], University of Neuchâtel, Institute of Microtechnique, Rue Breguet 2, Neuchâtel, CH-2000, Switzerland
Hiroyuki Fujiwara
Affiliation:
[email protected], AIST, RCPV, Umezono, Tsukuba, 305-8568, Japan
Get access

Abstract

Intrinsic hydrogenated amorphous silicon (a-Si:H) films can yield in outstanding electronic surface passivation of crystalline silicon (c-Si) wafers as utilized in the HIT (heterojunction with intrinsic thin layer) solar cells. We have studied the correlation between the passivation quality and the interface nature between thin amorphous layers and an underlying c-Si substrate for understanding the passivation mechanism. We found that a thin (∼5nm) intrinsic layer is inhomogeneous along the growth direction with the presence of a hydrogen rich layer at the interface and that completely amorphous films result in better passivation quality and device performance than an epitaxial layer. Post annealing improves carrier lifetime for the amorphous layer, whereas the annealing is detrimental for the epitaxial layer. We have also found that the passivation quality of intrinsic a Si:H(i) film deteriorates severely by the presence of a boron-doped a-Si:H(p+) overlayer due to Si-H rupture in the a-Si:H(i) film. Finally, for a passivation layer in the hetero-junction structure, a-Si1−xOx will be demonstrated in comparison with a-Si:H.

Type
Research Article
Copyright
Copyright © Materials Research Society 2008

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] Matsuura, H. Okuno, T. Okushi, H. and Tanaka, K. J. Appl. Phys. 55, 1012 (1984).Google Scholar
[2] Tanaka, M. Taguchi, M. Matsuyama, T. Sawada, T. Tsuda, S. Nakano, S. Hanafusa, H. and Kuwano, Y. Jpn. J. Appl. Phys. 31, 3518 (1992).Google Scholar
[3] Yablonovitch, E. Gmitter, T. Swanson, R.M. and Kwark, Y.H. Appl. Phys. Lett. 47, 1211 (1985).Google Scholar
[4] Taguchi, M. Terakawa, A. Maruyama, E. and Tanaka, M. Prog. Photovolt: Res. Appl. 13, 481 (2005).Google Scholar
[5] Wolf, S. De, Agostinelli, G. Beaucarne, G. and Vitanov, P. J. Appl. Phys. 97, 063303 (2005).Google Scholar
[6] Fujiwara, H. Kondo, M. and Matsuda, A. J. Appl. Phys. 91 (2002) 4181.Google Scholar
[7] Fujiwara, H. and Kondo, M. J. Appl. Phys. 101 (2007) 054516.Google Scholar
[8] Fujiwara, H. Koh, J. Rovira, P. I. and Collins, R. W. Phys. Rev. B 61 (2000) 10832.Google Scholar
[9] Fujiwara, H. Koh, J. Rovira, P. I. and Collins, R. W. Phys. Rev. B 61 (2000) 10832.Google Scholar
[10] Sinton, R.A. and Cuevas, A. Appl. Phys. Lett. 69, 2510 (1996).Google Scholar
[11] Taguchi, M. Kawamoto, K. Tsuge, S. Baba, T. Sakata, H. Morizane, M. Uchihashi, K. Nakamura, N. Kiyama, S. and Oota, O. Prog. Photovolt: Res. Appl. 8 (2000) 503.Google Scholar
[12] Cleef, M. W. M. van, Rath, J. K. Rubinelli, F. A. Werf, C. H. M. van der, Schropp, R. E. I. and Weg, W. F. van der, J. Appl. Phys. 82 (1997) 6089.Google Scholar
[14] Fujiwara, H. and Kondo, M. Appl. Phys. Lett. 90 (2007) 013503.Google Scholar
[15] Wolf, S. De and Kondo, M. in Proceedings of the 4th World Conference on Photovoltaic Energy Conversion, Waikoloa, Hawaii (IEEE, Piscataway, NJ, 2006), p. 1469.Google Scholar
[16] Wolf, S. De and Kondo, M. Appl. Phys. Lett. 90, 042111 (2007).Google Scholar
[17] Biegelsen, D.K. Street, R.A. Tsai, C.C. and Knights, J.C. Phys. Rev. B 20, 4839 (1979).Google Scholar
[18] Wang, T.H. Iwaniczko, E. Page, M.R. Levi, D.H. Yan, Y. Branz, H.M. and Wang, Q. Thin Solid Films 501, 284 (2006).Google Scholar
[19] Levi, D.H. Teplin, C.W. Iwaniczko, E. Yan, Y. Wang, T.H. and Branz, H.M. J. Vac. Sci. Technol. A 24, 1676 (2006).Google Scholar
[20] Beyer, W. Wagner, H. and Mell, H. Solid State Comm. 39, 375 (1981).Google Scholar
[21] Street, R.A. Tsai, C.C. Kakalios, J. and Jackson, W.B. Philos. Mag. B 56, 305 (1987).Google Scholar
[22] Beyer, W. Physica B 170, 105 (1991).Google Scholar
[23] Wolf, S. De and Beaucarne, G. Appl. Phys. Lett. 88, 022104 (2006).Google Scholar
[24] Wolf, S. De and Kondo, M. Appl. Phys. Lett. 91, 112109 (2007).Google Scholar
[25] Fujiwara, H. Kaneko, T. and Kondo, M. Appl. Phys. Lett. 91 (2007) 133508.Google Scholar