Greener method for recycling thin-film solar cells

Though silicon-based solar panels dominate with about 90 per cent of the market share, thin-film solar cells are growing in popularity, particularly in commercial and high-end applications. CIGS (Copper Indium Gallium Selenide) cells are some of the best performing, but the precious metals - indium and silver in particular – are in high demand and can be difficult to recover at end-of-life.

The Chalmers team used acid leaching to separate the metals from the other cell material, demonstrating that it is possible to recover 100 per cent of the silver and about 85 per cent of the indium. The process, described in the journal Solar Energy Materials and Solar Cells, takes place at room temperature without adding heat.

“Until now, high heat and a large amount of chemicals have been used to succeed, which is an expensive process that is also not environmentally friendly”, said Ioanna Teknetzi, PhD student at Chalmers’ Department of Chemistry and Chemical Engineering.