Researchers from the Adolphe Merkle Institute (AMI) at the University of Fribourg have developed a new type of more stable, highly efficient next-generation perovskite solar cell, opening perspectives for future commercialization. The results of their work have been published in the top-ranked journal Science.

Researchers are increasingly turning their efforts on perovskite solar cells, one of the most promising developments for photovoltaic energy. Perovskites have the material properties to become a serious contender for inexpensive solar energy production. The biggest roadblock to achieving this potential is the long-term stability of perovskite-based devices.
The research was carried out by Group Leader Dr. Michael Saliba at AMI. This time, the problem of the highly volatile and heat-sensitive methylammonium (MA) molecule was addressed. The most efficient perovskite solar cells contain unstable methylammonium (MA) molecules, mainly because of their capacity to provide high-performance values. By exchanging the organic MA with inorganic elements, the researchers have shown it is possible to avoid these unstable compounds while maintaining similar high efficiency. This allows for more stable solar cells, which is a key step towards eventual commercial use.
“These new perovskites can also harvest more sunlight, meaning they are more efficient and therefore more profitable,” explains Saliba. “In addition, these new materials are compatible with flexible substrates, making them useful for a wide variety of applications.”
“Essentially, this sets perovskites on the path of becoming a profitable, long-term solution for a sustainable energy future. With small additional improvements, perovskite solar cells can become a commercial reality within a short time.”

The results are published in the October 11 issue of Science.

This study was carried out in collaboration with the Hagfeldt group at the Laboratory of Photomolecular Science (LSPM) at the Federal Institute of Technology in Lausanne.

Reference
Silver-Hamill Turren-Cruz, Anders Hagfeldt, Michael Saliba, Demonstrating methylammonium-free, high-performance and stable perovskite solar cells on a planar, low-temperature architecture. Science 11 October 2018. DOI:10.1126/science.aat3583