New Solar Cell Process Saves $$$
Univ. of Utah Students Cut Germanium for Solar Cells
University of Utah engineers devised a new way to slice thin wafers of the element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by using less raw material and reducing waste.
Germanium solar cells, the most efficient solar cells, now are used mainly on spacecraft, but with the improved wafer-slicing method, “the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor,” particularly for solar power on Earth, says Eberhard “Ebbe” Bamberg, assistant professor of mechanical engineering.
Dinesh Rakwal, a doctoral student in mechanical engineering, adds: “We’re coming up with a more efficient way of making germanium wafers for solar cells – to reduce the cost and weight of these solar cells and make them defect-free.”
Bamberg and Rakwal are publishing their findings in the Journal of Materials Processing Technology. Their study has been accepted, and a final version will be published online late this month or in early October, and in print in 2009.
Their novel process uses a brass-coated, steel-wire to slice round wafers of germanium from cylindrical ingots. The brittle germanium cracks easily, requiring a saw with a soft touch. The width of the saw creates waste. In the past a significant amount of germanium is lost during the cutting process. The new U of U sawing method improves efficiency by about 10%.
The new method for slicing solar cell wafers – known as wire electrical discharge machining (WEDM) – wastes less germanium and produces more wafers by cutting thinner wafers with less waste and cracking. The method uses an extremely thin molybdenum wire with an electrical current running through it.
More Info at: U of Utah
September 24th, 2008 at 3:02 am
Finding a way to make solar cheaper is the only way it’s going to become a financially realistic power source for the masses. Let’s hope this leads to something big.
October 24th, 2008 at 1:49 pm
yes, the cheaper it is, the more popular it’ll be. this will in turn increase productivity and become cheaper still
June 12th, 2009 at 8:07 pm
It’s interesting that while solar technologies are almost always developed at universities, these institutions are still largely dependent on fossil fuels. One innovative way to increase demand for photovoltaics such that they can compete with conventional electricity production methods is to harness the green purchasing power of academic institutions (universities and colleges). This has been shown to be potentially quite influential in catalyzing a positive spiral-effect in renewables globally. Please see: Joshua M. Pearce, “Catalyzing Mass Production of Solar Photovoltaic Cells Using University Driven Green Purchasing”, International Journal of Sustainability in Higher Education, 7(4), pp. 425 – 436, 2006. at http://www.emeraldinsight.com/10.1108/14676370610702226