For all the great clean energy that solar cells generate, many of the materials used to manufacture them are not so great for the planet and human health. Once such chemical, cadmium chloride, is used to improve solar cell efficiency, but it's very toxic.
Researchers at the University of Liverpool believe they've found a substitute for that chemical that is much safer: a salt that is used to make tofu.
Magnesium chloride is a common salt that is also used in bath salts and for de-icing roads, but it could have one more great application. It's extracted from seawater and is far cheaper than cadmium chloride -- $0.001 per gram compared to $0.3.
Millions of solar panels around the world are made using cadmium chloride and for good reason -- it's great at boosting the conversion efficiency of solar cells. According to the university, the cheapest solar cells today are based on a thin film of insoluble cadmium telluride. On their own they are able to covert less than two percent of sunlight into energy, but when cadmium chloride is added, they can convert over 15 percent.
Lead researcher and physicist Dr. Jon Major says that the applying magnesium chloride provides the same boost, but it's far safer and far cheaper.
“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. Major.
“Cadmium chloride is toxic and expensive and we no longer need to use it. 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.”
Luckily, many other researchers are finding natural and safer materials to use in producing solar cells like wood fibers and biodegradable plastics. Soon solar panels could be just as clean as the energy they generate.