Researchers at Florida State University (FSU), in collaboration with ones from Argonne National Laboratory, have examined what happens when a halide perovskite faces real-world conditions, as opposed to pristine conditions of a chemistry lab.
They found that stressing halide perovskites with light and electric fields can create changes in the basic properties of the material and distort the lattice structure that is crucial to keeping this material stable.
“All of this goes back to building a better solar cell,” FSU Assistant Professor of Chemistry, Lea Nienhaus, said. “We needed to better understand what happens to this material when it is subjected to continuous illumination the way a solar cell would be if it were in use.”
While Nienhaus’ lab has been focused on ways to improve solar cells, she and some of her students started pursuing a side research project focused on why the halide perovskite films degrade so quickly under operating conditions.
For their study, Nienhaus and her collaborators used a technique called scanning tunneling microscopy that allowed them to study surface features and electronic properties of halide perovskites at the nanometer scale. By adding an illumination source to the system, they could monitor how the material changed under real-world conditions.
The researchers also used two synchrotron-based techniques available at the Advanced Photon Source at Argonne National Laboratory to correlate the observed optical changes to structural ones within the halide perovskite film.
“If we can pinpoint areas of structural change which are the origin of degradation, then we can start working on mitigation strategies that will ideally help us build a better halide perovskite film and thus a solar cell,” Nienhaus said.
In October 2020, Florida State University (FSU) researchers gained better understanding of the fundamental processes in perovskites. As art of this task, they found that small tweaks to the chemical makeup of the materials as well as the magnitude of the electrical field it is exposed to can greatly affect the overall material stability.