Inspired by an inorganic chemistry seminar course for first-year undergraduates, a research team led by Zheng Nanfeng, an academician of the Chinese Academy of Engineering, and Professor Wu Binghui of Xiamen University has developed a Prussian blue-based strategy to improve the efficiency and stability of perovskite solar cells, achieving a certified power conversion efficiency of 22.9 percent in large-area submodules.
Conducted in collaboration with researchers from Jinan University, Tsinghua University, Xi'an Jiaotong University, Uppsala University in Sweden, and research institutes of the Chinese Academy of Sciences, the study, titled "Prussian blue regulates ion dynamics in perovskite solar cells", was published online in Science.
The researchers used Prussian blue, an open-framework material, to regulate both crystallization and ion migration. In situ grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements showed that the framework guided crystal formation toward the photoactive α-FAPbI₃ phase while suppressing non-photoactive phases and reducing tensile strain. X-ray absorption fine structure (XAFS) analysis further showed that the framework retained its structural integrity during cation incorporation and redox reactions, helping regulate ion movement.
The team used synchrotron-based characterization at the Beijing Synchrotron Radiation Facility to investigate these mechanisms.
The strategy achieved a champion power conversion efficiency of 26.9 percent in small-area cells, with a certified efficiency of 26.2 percent. It also achieved 23.4 percent efficiency in 6-by-6-centimeter minimodules and a certified 22.9 percent in 30-by-30-centimeter submodules.
The findings offer a potential route to developing efficient, stable perovskite solar cells at larger scales.
