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Doped Self-Aligned Metallization for Solar Cells

Published online by Cambridge University Press:  03 March 2011

Ernest A. Addo
Affiliation:
Department of Material Science and Engineering, University of Delaware, Newark, Delaware 19716, and AstroPower Inc., Newark, Delaware 19716
S. Ismat Shah
Affiliation:
Department of Physics and Astronomy and Department of Material Science and Engineering, University of Delaware, Newark, Delaware 19716
Robert Opila
Affiliation:
Department of Material Science and Engineering, University of Delaware, Newark, Delaware 19716
Allen M. Barnett
Affiliation:
AstroPower Inc., Newark, Delaware 19716
Kevin Allison
Affiliation:
AstroPower Inc., Newark, Delaware 19716
Oleg Sulima
Affiliation:
AstroPower Inc., Newark, Delaware 19716
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Abstract

Metal contacts using doped self-aligning metallization to [100] and [111] p-type silicon were investigated. Contacts formed in this manner allow the formation of a pn-junction and provide front metallization for photovoltaic applications. Formulated screen-printable thick films were annealed above Ag/Si eutectic temperature of 830 °C. The annealing process resulted in a junction depth of 0.3–1.1 μm with improved Ag/Si metal contacts due to the reduction of parasitic native oxide layer via the use of a wetting agent. The technique inhibits shunts (high conductivity paths through the solar cell pn-junction caused by excessive metal penetration) due to limited solubility of Ag in Si. The technique also reduces series resistance (a parasitic resistance due to surface states that also limit solar cell performance) due to a robust thermal processing window. The use of magnesium (Mg) as a wetting agent in the thick film Ag matrix was explored. We observed a correlation between increased wetting and improved dark saturation current J02 in the absence of a pre-existing junction.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1Ross, B.: IEEE PVSC. 14, 787 (1980).Google Scholar
2Meier, D.L., Davis, H.P., Garcia, R.A., Jessup, J.A., Hacke, P., Yamanaka, S. and Salami, J. in 11th NREL Workshop on Crystalline Silicon Solar Cell Materials and Processes (2001), p. 129Google Scholar
3 A.S.M. Alloy Phase Diagrams. ASTM 3 2–37 (1985).Google Scholar
4Smith, D.D. in 9th NREL Workshop on Crystalline Silicon Solar Cell Materials and Processes, (1999), p. 62Google Scholar
5Popovic, R.S.: Solid State Electron. 21, 1133 (1978).CrossRefGoogle Scholar
6Meier, D., Davies, H.P., Garcia, R.A. and Carroll, A.F.: IEEE PVSC. 28, 69 (2000).Google Scholar
7Frisson, L., Lauwers, P., Bulteel, P., De Smet, L., Mertens, R., Govaerts, R. and Van Overstraeten, R.: IEEE PVSC. 13, 590 (1978).Google Scholar
8Field, M.B.: IEEE PVSC. 12, 303 (1976).Google Scholar
9Sulima, O.V., Jonczyk, R., Kirpalani, N.L., Paulson, P.D., Datta, S. and Rand, J. in 12th NREL Workshop on Crystalline Silicon Solar Cell Materials and Processes, (2002), p. 224Google Scholar
10Leedy, K.D. and Rigsbee, J.M.: J. Vac. Sci. Technol. A. 14, 626 (1996).CrossRefGoogle Scholar
11 PAX-It: Imaging System for Scientist, MIS (2000)Google Scholar
12Wolf, M. and Rauschenbach, H.Adv. Energy Con. 455, (1963)Google Scholar
13Cheek, G.C., Mertens, R.P., Van Overstraeten, R. and Frisson, L.: IEEE Trans. Elect. Dev. 31, 602 (1984).Google Scholar
14Nakajima, T.: in Proc. 2nd Int. Microelect. Conf. (1984), p. 580.Google Scholar
15Ross, B.: IEEE PVSC. 14, 1406 (1980).Google Scholar
16Reimer, D.E.: IEEE PVSC. 13, 603 (1978).Google Scholar
17Schroder, D.K. and Meier, D.: IEEE Trans. Elect. Dev. 31, 647 (1984).Google Scholar
18Lin, H.C., Spittlehouse, D.P. and Hsueh, Y.W.: IEEE. PVSC. 13, 593 (1978).Google Scholar
19Dziedzic, A., Nijs, J. and Szlufcik, J.: J. Int. Soc. Hybrid Microelect. 30, 18 (1993).CrossRefGoogle Scholar
20Rohatgi, A., Meier, D.L., Hilali, M., Jeong, J.W. and Carroll, A.F.: IEEE PVSC. 29, 356 (2002).Google Scholar