Text: Anne-Lise Aakervik
The solar cell industry is booming, and there is an ever-increasing demand for more and better solar cells. Solar cells are currently made from silicon ingots cast in crucibles made of high-purity quartz (see illustration 1). Quartz crucibles are expensive, but they still need to be discarded after having been used just a few times, due to cracks and impurities. The discarded material contains silica (quartz is converted to silica in the casting process), in addition to silicon residue at the bottom of the crucible. These materials are valuable if properly recycled.
This challenge was nothing new to researchers Erik Larsen and Rolf Arne Kleiv at the Department of Geoscience and Petroleum. They started looking into the possibility of recycling. Erik Larsen had an epiphany when he visited a manufacturer and noticed piles of scrap crucibles outside the factory. “There has to be a way we can fix this,” Larsen thought.
Norway is one of the biggest manufacturers in Europe, but we are still relatively small compared to the Asian market in terms of silicon casting for solar cell production.
In the lab, Erik Larsen is demonstrating a part of the process they want to test on a large scale. If all goes well, the team behind SiQua hope that the market will embrace the new process.