The promise of using perovskite-based solar cells to replace silicon-based modules has been around for years, but so far the technology hasn’t advanced enough to compete effectively on the mainstream market.
Researchers at the University of Toledo (UToledo) may have now devised a solution to this problem with a new chemical formula and process for making perovskite cells for full-sized solar panels in the consumer market.
|Professor Zhaoning Song of the University of Toledo holds a perovskite solar cell mini-module he developed with his colleague Professor Yanfa Yan. The higher-efficiency, lower-cost solar cell technology could revolutionize energy generation around the globe. (Image source: University of Toledo)|
The Next Generation?
Perovskites are compound materials with a crystal structure that long have been viewed as a leading next-generation material in a type of solar cells called thin-film. The material has a number of advantages over silicon, including higher efficiency and less cost in cell production.
One drawback to the research, however, has been to create a perovskite cell with efficiency on par with current silicon-based solar panels, which have about an 18 percent efficiency rating.
The UToledo team now has achieved a perovskite-based solar cell with about 23 perfect efficiency by fine-tuning a mix of lead and tin to advance the technology closer to its maximum potential, showing promise for bringing perovskite cells to market, Zhaoning Song, research assistant professor in the UToledo Department of Physics and Astronomy, told Design News.
“We aim to develop the next generation of solar cells that could achieve high efficiency to convert sunlight into electricity while retaining low manufacturing costs,” he said.
The team, led by Yanfa Yan, UToledo professor of physics, worked with the U.S. Department of Energy’s National Renewable Energy Lab on the latest research.
Different Parts of the Spectrum
About five years ago, Yan and his colleagues identified the ideal properties of perovskites. That work now has produced an all-perovskite tandem solar cell that brings together two different technologies using two different parts of the sun’s spectrum to generate more electricity.
“This is the material we’ve been waiting for for a long time,” Yan said. “The solar industry is watching and waiting. Some have already started investing in this technology.”
Perovskites typically consist of lead, tin, iodine, bromine, and other elements, Song told us. In their current work, the team used a chemical compound called guanidinium thiocyanate to improve significantly the structural and optoelectronic properties of their solar-cell materials, he said.
“We used solution routes to synthesize the lead-tin mixed perovskite materials,” Song explained. “Perovskites are better than silicon at absorbing photons from the sunlight and are easier to manufacture than silicon. We combined two layers of perovskite with complementary absorption of the solar spectrum to harness more solar power.”
Finally Commercially Viable
With their solar cells reaching a performance efficiency of more than 23 percent, researchers believe their technology could represent the future of commercially available solar panels, he said.
“Our research shows the promise to achieve high power-conversion efficiency using the tandem structure of the perovskite materials,” Song said. “The advance could eventually lead to less costly solar power.” Researchers published a paper on their work in the journal Science.
While the team’s research is promising, Song said researchers still have some significant work to do before the technology is optimized for the solar industry.
“The material cost is low and the fabrication cost is low, but the lifetime of the material is still an unknown,” he said. “We need to continue to increase efficiency and stability.”
The team also needs to carefully consider the use of the toxic substance lead in its technology to ensure there is no detrimental effect on the environment, Yan added.
Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 20 years. She has lived and worked as a professional journalist in Phoenix, San Francisco and New York City. In her free time she enjoys surfing, traveling, music, yoga and cooking. She currently resides in a village on the southwest coast of Portugal.
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