Posted on April 26, 2019
by Steve Henley
April 26, 2019 from Steve Henley
Many important discoveries are the result of accidents. Researchers who want to make super-strong adhesives for sticking parts of aircraft together have led to the creation of one of the least sticky substance known to science. Re-set to make notes from Post-It, those small pieces of paper that can hardly hold onto the fridge. WD-40 was intended as a spray substance that would replace water from metal surfaces. WD section refers to "moving water". Part "40" represents the other 39 non-working attempts.
People mocked Thomas Edison while trying hundreds of materials for the filament of an electric bulb. Not everyone has succeeded. "It just means I'm very close to finding something that works," he reportedly told his slanderers. Then he tried tungsten wire, and the rest, as they say, is history.
In theory, Perovskites need to make solar cells that are cheaper because they use elements that are abundant in nature. The original Peruvian solar cells had an efficiency of about 1%. Today, non-tandem Peruvian solar cells can achieve efficiency up to 24.2%, but still suffer from several disadvantages. They do not last very long and are disintegrated in the presence of water and other pollutants. There is no way the solar panel using cells made from perovskite can be performed safely in the wild for 20 years or more as conventional solar panels do.
Researchers at the University of California Los Angeles believe they may have found a way to improve the performance of Perovskites. They sat around drinking coffee in the cafeteria one day, demanding an energy boost, when one of them suggested that caffeine should try to improve the performance they worked in the lab. So they are.
It was a moment of "pure happiness," said UCLA engineer Yang Yang, a faculty adviser to graduates. "We needed some molecule with lone electronic pairs," he says Scientific American. As it turns out, caffeine is just one type of molecule that they are looking for. The survey was published this month in the magazine Joule.
Caffeine allows Perov crystals to form without such a "disturbance" like those that are grown without it, says Joseph Barry, physicist at the National Renewable Energy Laboratory, who was not involved in the research. "In general, the perspective is:" If you make the material superficially, you get something that is better. "Caffeine, at local level, ensures that you get material that is a little more structured," he says. "This results in a more stable device".
"Basically, these peruvian materials offer functionality that can not coincide. We're just beginning to understand them well enough to start engineering things," he adds. "That's why these Yang results are so appealing." A new research survey can help scientists discover or design new molecules that stabilize Peruvian solar cells even better than caffeine.
Jinsong Huang, a physicist at the University of North Carolina Chapel Hill, believes this new discovery could help Peruvian solar cells closer to commercial sales. "Stability is the last obstacle we need to overcome [for perovskite cells] to enter the market. You can make solar cells more efficient and more stable in other ways. But this is a very good result, and it opens our mind to different materials that you never thought would work. "
Caffeine-infused perineal cells have proved more durable than conventional perovskite and have increased the efficacy of 16% (primary / standard cells) to 20%. (Note: it is still less than 24.2% effective non-tandem cells.)
Tandem perovskite has reached almost 30% efficiency in the laboratory. Imagine what they can achieve if they use caffeine cells. "Tandem solar cells are just like a double bus," says Yang. "Something that helps the one-stop bus can help the two-seater bus."
Making Perovskite is easy, says Yang. "We only buy chemicals and mix them in our laboratory in a glass. It's like cooking, then we put a little caffeine in the liquid, and we fit everything evenly." Finally, the mixture pours through the glass to create first-class crystals. "A high school student can make a Perovsk solar cell in our laboratory," says Yang.
Some may recall that Perovskites are far from decaying from the laboratory and commercial production. That's true, but it was not so long ago that the light from LEDs was so weak, people wondered if they would ever have a useful purpose. Never say never, in other words. Cheap solar panels made from easily accessible materials can be closer than we think.