Scientists devise unique method to recover rare metals for low-cost CIGS solar cells
In purely statistical terms, the growth rate of thin film solar cell market touched a whopping 60 percent benchmark from 2002 to 2007. Suffice it to say, such kinds of advanced CIGS solar cells do account for a crucial commercial chunk of renewable energy. But the predicament lies with their relatively high-cost of manufacturing and usage, partly due to the technology’s utilization of expensive rare earth materials like Gallium and Indium. Fortunately, scientists are looking forth to a solution that can significantly alleviate this high cost factor. Midsummer, a company dealing with cost effective production of CIGS solar cells, has collaborated with Professor Christian Ekberg and PhD-student Anna Gustafsson (from Swedish Chalmers University of Technology) to develop a special procedure that can effectively recover the leftover rare metals after a conventional manufacturing process (of solar cells).
According to the scientists involved, the leftover rare metals account for a substantial 30 to 40 percent of deposits masking the manufacturing machines. Their new technique will allow the removal of selenium by use of oxygen, which makes its much easier to process the remaining metals (as opposed to melting all the materials in an unrefined manner). There is a two-fold advantage to this unique method – firstly, because selenium in heated mode can lead to toxic gases; and secondly, the separated selenium (with high purity) can be further re-utilized to produce more solar cells.
In other words, the recycling scope will lead to significantly reduced material costs for thin film CIGS solar cells, while at the same time making the production environment safe for workers. Conveniently, this recovering method will also complement Midsummer’s proprietary process of making cadmium-free CIGS on stainless steel.