New Method Cuts Waste In Making Most Efficient Solar Cells
The new method for slicing [germanium] solar cell wafers – known as wire electrical discharge machining (WEDM) – wastes less germanium and produces more wafers by cutting even thinner wafers with less waste and cracking. The method uses an extremely thin molybdenum wire with an electrical current running through it. (...)The process is slow. Wire electrical discharge machining takes 14 hours to cut a single wafer. Bamberg says the electrified wire method has to be done gently to avoid cracking the germanium, but he hopes to increase the speed to the six hours it now takes to cut a wafer using a wire saw.