Researchers from Stanford University in the US state of California have developed and tested a new material that can cool solar cells by up to 13 degrees Celsius, thereby increasing their efficiency and lengthening their lifespan.
To be more specific, the researchers have used an approach called “radiative cooling”. They have managed to maintain sunlight absorption and at the same time achieve the cooling effect with a wafer made of silica, a colourless mineral found naturally as quartz.
The researchers etched tapered holes in the wafer to smooth the path the thermal radiation takes to escape. They tested the transparent silica layer by placing it on top of a solar cell mimic, a polished silicon wafer that was not actually wired to generate electricity. This verified that there was a slight rise in absorption because of anti-reflection and the light trapping effects of the etched silica.
According to the team, the 13 degrees cooling would help boost efficiency by more than 1%. The researchers say that the improvement is significant considering the fact that this is “a relatively simple add-on”.
Now, the team will test the etched silica layer with a real solar cell to demonstrate the predicted efficiency improvements.
This cooling approach can be applied in cars, clothing and outdoor equipment as well, says graduate student Linxiao Zhu, part of the research group of electrical engineering professor Shanhui Fan.
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