Researchers develop technique to use dirty silicon, could pave way for cheaper solar energy

My Thoughts: the wonders of materials science: Annealing the Silicon allows the iron ion impurities to gather in less disruptive patterns within the silicon wafer. Similar to Annealing Glass in an Oven to remove stress within the structure of a vessel created from "the supercooled metalic liquid" that the world calls "Glass". Researchers develop technique to use dirty silicon, could pave way for cheaper solar energy: "The researchers found that they were able to manipulate the distribution of the metal impurities by varying the cooling rate of the silicon. When the material is cooled quickly, the metal defects are quickly locked in a scattered distribution. By simply slowing down the cooling rate, the metal impurities diffused into large clusters.

'Using this cooling technique, we were able to improve the distance electrons could travel by a factor of four compared with dirty silicon that had been left unaltered,' said Buonassisi. 'Although this is still not as efficient as ultrapure silicon, it is the proof of principle that poor-quality silicon can be easily improved. We are now looking at other techniques that could further enhance the efficiency of dirty silicon.'

The researchers point out that techniques such as varying the cooling rate of silicon is an easy, cost-effective adjustment to current manufacturing procedures. "