A set of patents published this month focussed on tin innovations for solar cell interconnection, reflecting the importance of this exponentially growing new market.
At present cells are typically joined using a mainly tin-lead solder-coated copper wire and lines of expensive silver-based connection strips on the front and back. Du Pont published a patent that completely replaced silver on the back and possibly also the entire aluminium back layer, by a tin-aluminium paste material. Samsung patented the additional use of up to 15% tin on the front silver electrodes. Both Hitachi and a Korean supplier published patents on improved methods for solder coating the copper wire.
Installed solar capacity is expected to grow from 290 GW in 2016 to around 2,000 GW by 2030.