摘要 |
Disclosed are silicon-free aluminum paste compositions for forming an aluminum back electrode with large silicon particles, processes to form aluminum back electrode of solar cells, and the solar cells so-produced. The process applys a silicon-free aluminum paste on a back surface of a p-type silicon substrate. The silicon-free aluminum paste compositions have an additive comprising calcium oxide, calcium oxalate, calcium carbonate, calcium phosphate, or mixtures thereof; an aluminum powder; and an organic vehicle. The process also applys a metal paste on a front side of the p-type silicon substrate and firing the p-type silicon substrate after the application of the aluminum paste at a peak temperature in the range of 600-950° C., whereupon firing the additive promotes a growth of silicon particles having an equivalent diameter in the range of 2-15 microns in a particulate layer of the aluminum back electrode.
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