Silver is an expensive material which cannot easily be replaced, as its high conductivity is equalled or overtaken only by even more expensive materials such as gold and platinum. The silver market fluctuates according to demand, and the price volatility of silver is notorious. Virgin silver production has well known damaging environmental effects (mercury pollution). As already mentioned, the PV sector has put efforts into reducing the silver consumption per solar cell, but now seems to have reached a bottom line. Due to the rising scale of global production, PV is responsible for 15% of the overall market demand for silver. Silver is already recycled in many industries. The eco-efficiency of PV should be increased by a further reduction of silver consumption, recycling silver from PV waste and using secondary material.

The use of secondary silver recycled from PV waste for the production of conductive pastes and inks for PV manufacturing. The used polymer matrix is based on polysiloxanes which have superior properties as opposed to acrylates, especially in terms of resistance to higher temperatures. In addition, silver-coated copper particles have been tested as a lower-cost alternative. The results have shown that the compatibility of the silver-copper particles with silver nanoparticles, added to maximize conductivity, is excellent.

What is new?

• Produce silver-based conductive pastes and inks using silver-coated copper particles taking advantage of copper’s high electrical conductivity and oxidation resistance from the silver coating
• CABRISS-developed processes of recovering silver as a chloride salt have been shown to be viable in the preparation of these silver-coated copper powders
• Reduce the cost by using only 30% of the silver volume that is normally used with silver pastes and inks