Mild oxalic acid process recovers indium from heterojunction solar panels

⚡ AI Executive Summary

Researchers at France's CEA-Liten laboratory have developed a chemical recycling process for recovering indium from discarded heterojunction solar panels using diluted oxalic acid instead of stronger mineral acids. The method achieves high-purity indium recovery in a single chemical step while also enabling silver grid separation from silicon wafers. This work addresses a growing sustainability challenge as heterojunction solar technology scales globally: the indium tin oxide layers in these high-efficiency cells represent both valuable material and waste-management complexity. The mild-acid approach could reshape solar panel end-of-life economics, reducing hazardous chemical exposure in recycling facilities and improving recovery economics for manufacturers. As heterojunction production accelerates, efficient indium recycling will become critical to supply-chain resilience and the circular economy ambitions of the solar industry.