Researchers from South-Africa's University of the Western Cape, University of Missouri and Argonne National Laboratory have developed a new way of enhancing the stability and performance of perovskites.
Missouri University professor Suchismita (Suchi) Guha, the lead author of the study, and her collaborators improved the methods for making lead halide perovskites. Previous techniques for making these thin-film perovskites required liquid processing using solvents, which rendered the films susceptible to degradation when exposed to air. Additionally, with prior manufacturing processes, one of its molecules undergoes a change to its structure, causing performance limitations in real-world operating conditions.
With the new technique, the researchers were able to prevent the change, holding the affected molecule in a stable structure throughout a large temperature range. Additionally, the new technique rendered the perovskite air stable, making it appropriate for a potential solar cell.
“There have been many studies that have looked at ways to try to improve the stability of hybrid perovskites, including diffusion barriers, additive engineering, and chemically inert electrode optimization, but this is one of the first studies to look at the growth method itself as a way to boost the final performance of the device,” Guha said.
To confirm the molecular structure of the perovskite material, Guha and her colleagues, including Argonne physicist Evguenia (Jenia) Karapetrova, used X-ray diffraction measurements at Argonne’s Advanced Photon Source (APS), a DOE Office of Science user facility.
“Being able to characterize the perovskite structure at the APS provides a unique window into the possibilities of this functional material,” Karapetrova said.
“Preventing the phase change seems to be the key to ensure improved device performance,” Guha said. “By maintaining a stable structure throughout the operating temperature window, we show the way to an improved and potentially useful perovskite.”