Ever heard of perovskite solar cells?

If not, you will. A perovskite is a material with a certain type of crystal structure. In 2009, researchers began using perovskites instead of the usual silicon to make solar cells.

Those first perovskite cells converted only 3.8% of the sun's energy into electricity. Now, a new type of perovskite solar cell has achieved 25% efficiency. So in just 10 years, the efficiency of the perovskite technology has increased by 558%. (Today's commercially available silicon-based solar panels top out at 22.2% efficiency.)

Researchers at the US National Renewable Energy Laboratory worked with scientists at the University of Toledo (Ohio) and the University of Colorado to achieve the breakthrough. They published an article about their findings May 3 in Science.

"This is the material we've been waiting for for a long time," said Yanfa Yan, professor of physics at Toledo, quoted in a university news release. "The solar industry is watching and waiting. Some have already started investing in this technology."

Yan was one of the Science article authors, along with Toledo colleague Zhaoning Song, research assistant professor in the Department of Physics and Astronomy. In April, Yan's laboratory received a $1.1 million US Department of Energy grant to continue his research in collaboration with the National Renewable Energy Lab.

Unlike silicon solar cells, perovskite cells can flex and should be cheaper to make at industrial scale. The researchers are still working on the mix of materials. Most perovskite cells are lead-based. Adding tin and guanidinium thiocyanate has improved performance. Expect more tinkering.

"The material cost is low, and the fabrication cost is low, but the lifetime of the material is still an unknown," Song said. "We need to continue to increase efficiency and stability."

The researchers are addressing other concerns as well. "Lead is considered a toxic substance," said Yan. "I am determined to work with the solar industry to ensure solar panels made of this material can be recycled so they don't cause harm to the environment."