Megan Fellman, reporting for Northwestern University in Evanston, Illinois, explains a possible breakthrough in obtaining power conversion efficiency for polymer (plastic) solar cells close to those for more expensive silicon cells. Fellman lists the benefits of the plastic cells: “Among the various photovoltaic technologies, polymer (plastic) solar cells offer unique attractions and opportunities. These solar cells contain Earth-abundant and environmentally benign materials, can be made flexible and lightweight, and can be fabricated using roll-to-roll technologies similar to how newspapers are printed. But the challenge has been improving the cells’ power-conversion efficiency.” Faculty members and students led by Professor Tobin J. Marks designed and synthesized new polymer semiconductors, “and reports the realization of polymer solar cells with fill factors of 80 percent – a first. This number is close to that of silicon solar cells.” “Fill factor” is a measure of the ratio of the maximum power from the solar cell to the product of Voc (open-circuit voltage) and Isc (short-circuit current). The link …
More Heat Than Light – But Energetic, Nevertheless
Mars Curiosity Rover is bigger than one would expect, over six feet tall and weighing 1,982 pounds. It travels up to 660 feet per day on its multiple wheels, looking for rocks to analyze with its ChemCam. Powered by the heat from its plutonium reactor, Curiosity will rove Mars for two years if all goes well. The heat is converted to electricity (which then drives the wheel motors on the rover) by a lead telluride thermoelectric material, a semiconductor which, capable as it is, has been eclipsed in efficiency by a new form of the material developed by Northwestern University researchers. Mercouri G. Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences, explains that his heat exchange material is twice as efficient as that used on Curiosity, a breakthrough with potential uses to boost car mileage, improve industrial processes, and maybe even make hybrid aircraft more efficient. Currently used materials have …