Copper is significantly cheaper than silver, it is much more readily available and is already recycled in large quantities. The only disadvantage is that copper damages the silicon material when it penetrates. A new electroplating process minimizes this risk. The efficiency and performance of the solar cells produced in this way are maintained or even improved. If Fraunhofer ISE has its way, the new electroplating process will be used for the production of the next generation of silicon solar cells in just a few years. The results of two projects funded by the German Federal Ministry for Economic Affairs and Climate (BMWK) show that the Institute is well on the way: a research team at the Institute metallized bifacial TOPCon solar cells with galvanic nickel/copper/silver contacts. Silver consumption was reduced by 90 percent. The cells achieved an efficiency of 24 percent, 0.5 percent higher than conventional cells metallized with silver screen printing. Another process for galvanic copper metallization is currently being developed at Fraunhofer ISE: silicon heterojunction solar cell technology is also suitable for greatly reducing silver consumption. The researchers' galvanic copper metallization addresses several issues: the laser contact aperture is reduced, the type of laser structuring also allows the conductor tracks to be made narrower, and aluminum is used for masking instead of lacquers or foils.
Read the article on this in mo 11 2022 or online here!