Tofu Chemical Could Prompt New Wave of Solar Cells
Solar cells could learn a thing or two from tofu and bath salts.
Researchers from the Stephenson Institute for Renewable Energy at the University of Liverpool in England have found that magnesium chloride (MgCl2) – found in tofu, bath salts and de-icing solutions – may produce more cost-effective and efficient solar cells. The compound could serve as a replacement for cadmium chloride (CdCl2), a toxic ingredient frequently used in solar cell technology, the researchers said.
CdCl2 is expensive to produce and requires extensive safety measures during solar cell manufacturing, the researchers said. In contrast, MgCl2 – which is extracted from sea water – is much safer, demonstrates energy efficiency similar to the toxic alternative, and is much less expensive to produce.
Other inexpensively manufactured solar cells, based on thin films of insoluble cadmium telluride, do exist, but are less efficient, as they are only able to convert less than 2 percent of sunlight into energy, according to the researchers. Applying cadmium chloride to them raises the efficiency above 15 percent.
Magnesium chloride, the researchers have found, achieves the same result – and with fewer safety restrictions. “We have to apply cadmium chloride in a fume cupboard in the lab, but we created solar cells using the new method on a bench with a spray gun bought from a model shop,” said Dr. Jon Major, a physicist at the institute.
“Cadmium chloride is toxic and expensive, and we no longer need to use it,” Major added. “Replacing it with a naturally occurring substance could save the industry a vast amount of money and reduce the overall cost for generating power from solar.”
The work was funded by a grant from the Engineering and Physical Sciences Research Council and the University of Liverpool. The study was published in Nature (doi: 10.1038/nature13435).
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