MIT researchers claim 50% increase in solar-cell output
By Matthew Miller, Editor-in-Chief, EDN.COM -- EDN, January 8, 2009
A team of physicists and engineers at MIT (Massachusetts Institute of Technology) claims that sandwiching a solar cell between an antireflective coating on the front and a combination of reflective coatings and a diffraction grating on the back can increase the cell's output by as much as 50% for a 2-micron-thick cell.
The aim of the coatings and grating is to keep photons of incoming light bouncing around longer within the thin silicon cell, thereby increasing the likelihood that they will deposit their energy and produce a current rather than just escaping back out into the surrounding air. The team used simulation to experiment with the spacing of the diffraction grating's lines, the number and thickness of reflective coatings, and the thickness of the silicon before verifying the findings in the lab.
Because the work applies to extremely thin silicon cells, the researchers cite reduced silicon cost as another benefit of their approach, stating that their thin films use about 1% as much silicon as conventional solar cells.
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50% better than what? How can we compare the results if the output is not listed?
Mike Weber - 2009-29-1 15:37:00 PST -
I find the solare cell increased output to be very
encouraging. The better they work the quicker we can
use them to escape the oil dependency.
Have you checked the efficiency of the cells in a very
hostile environment or simulated sand, rain, snow, dirt
buildup, rock dammage along the roadway for mobile
solar arrays, etc?
Remember, until you use it, it is worthless.
I have evaluated electronics extensively and know that
murphy has to be overcome in the real world. You can
do it, but need to test it to optimize the results.
Thanks for caring,
Gerald Bryan
Gerald D. Bryan - 2009-16-1 11:21:00 PST -
That is excellent news and hope it can be substantiated soon commercially. I come from Chennai, India and this concept and improved conversion efficiency would go a long way for lighting up remote villages with LED lighting. Please keep me posted on further improvements in this direction.
K.T.Kuruvilla - 2009-14-1 20:38:00 PST -
Simulation is all well and good, but now it must be built to prove such claims. Using 1% as much Silicon as conventional solar cells sounds good, but there is still a need for a good, clean substrate on which to deposit the Silicon. This could easily be equal to or exceed the cost of a Silicon substrate. It would be good to know the estimated costs adder of the grating and coating steps. It all comes down to cost per watt. The benefit of higher power density is only a secondary factor.
David Buraczyk - 2009-13-1 11:47:00 PST
