Scientists studied the inner workings of a solar cell material using X-ray and neutron scattering. The study revealed that liquid-like motion in the material may be responsible for their high efficiency in producing electric currents from solar energy.

Perovskites, a class of materials with a unique crystal structure, could overtake current technology for solar energy harvesting. They are cheaper than materials used in current solar cells, and they have demonstrated remarkable photovoltaic properties — behavior that allows them to very efficiently convert sunlight into electricity.

Revealing the nature of perovskites at the atomic scale is critical to understanding their promising capabilities. This insight can help inform models to determine the optimal makeup of perovskite materials for solar cells, which can be used to power vehicles, electronic devices and even home heating and other appliances.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory participated in a collaboration led by Duke University, along with DOE’s Oak Ridge National Laboratory and other collaborators, to study the inner workings of a perovskite material using the world-class X-ray scattering capabilities at Argonne and neutron scattering capabilities at Oak Ridge. The scattering capabilities enabled the scientists to observe the material’s behavior at the atomic scale, and the study revealed that liquid-like motion in perovskites may explain how they efficiently produce electric currents.

«There is a lot of excitement surrounding these materials, but we don’t fully understand why they are such good photovoltaics,» said Duke University’s Olivier Delaire, lead scientist on the study.

When light hits a photovoltaic material, it excites electrons, prompting them to pop out of their atoms and travel through the material, conducting electricity. A common problem is that the excited electrons can recombine with the atoms instead of traveling through the material, which can significantly decrease the electricity produced relative to the amount of sunlight hitting the material.

Story Source: Materials provided by DOE/Argonne National Laboratory. Original written by Savannah Mitchem. Note: Content may be edited for style and length.