- Number 341 |
- July 11, 2011
NREL invention speeds solar cell quality tests
Inside the FlashQE, developed
at NREL, light from LEDs is
focused onto a solar cell.
To come up with a way to do something 1,000 times faster than it had been done in the past, you have to count on some serendipity – not to mention hard work, collaboration and good timing.
Such was the case with three scientists from DOE’s National Renewable Energy Laboratory, who somewhat accidentally developed a way to assess the quality of solar cells at a speed that is orders of magnitude faster than had been done before.
The instrument, Real-time QE, licensed and embellished by Tau Science Corp. as FlashQE™, uses light-emitting diodes, high-speed electronics and mathematical algorithms to measure the quantum efficiency of solar cells up to 1,000 times faster than had been done before. The technology won a 2011 R&D 100 Award, as one of the year’s most significant innovations.
What used to take 20 minutes – and therefore could be done only with random samples of cells – now can be done in a second. That means every single cell on a manufacturing line can be assessed and then sorted into bins so the cells that respond best to, say, red or blue are kept together on the same solar module. That way, a mismatched blue-response cell on a module won’t put the brakes on all the work the red-response cells are doing. And that means more efficient conversion of photons into electricity at sunrise and sunset when the red wavelengths predominate.
Traditionally, determining how a single cell responds to different wavelengths of light has taken 20 minutes, so only about one in 1,000 cells are plucked from the manufacturing process for that extra test.
Flash QE, though, has the speed to supply that extra rich information for every cell.
It likely will mean significant jumps in the efficiency values of future solar modules and arrays that power the fast-growing solar industry as well as much better manufacturing line diagnostics.
FlashQE comes on the market at a time when solar manufacturers are working to weed out any profit-robbing costs from their production lines, boost the conversion efficiencies of solar cells, and move toward the U.S. Department of Energy cost goals established within the “SunShot” initiative.
NREL’s LED light source also is a stand-alone invention that could be licensed by another company for probing things other than solar cells, ranging from counterfeit bills to skin cancer. For more on Flash QE, see the NREL feature story.
[Bill Scanlon, 303.275.4051,