Solar PV silicon recycling via chemical and vacuum refining techniques

This poster presents the APOLLO project research conducted by the NTNU and SINTEF team, which investigates advanced chemical and vacuum refining techniques to enable complete recycling of photovoltaic (PV) silicon. The aim is to meet the 6N purity standard (99.9999%) needed for reuse in solar applications. By combining acid and alkaline leaching with high-temperature vacuum refining (1450 °C, 0.05 mbar), researchers successfully lowered impurity levels to 16 ppm—an order of magnitude closer to the target. The study emphasises the potential of integrating surface impurity removal and bulk purification methods to efficiently recover high-purity silicon from end-of-life PV panels.