This week is the week that The University of Toledo has reported on a research project that passedivated reactive areas in the crystal structure in order to prevent the crystal from failing.
Perovskite solar cells are a new type of solar cell that have gained significant attention in the scientific community due to their high efficiency and low production cost. These solar cells are named after the mineral perovskite, which has a similar crystal structure to the material used in the solar cells. Perovskite solar cells use a thin film of perovskite material to absorb sunlight and convert it into electricity. The perovskite material has unique properties that allow it to efficiently capture light and convert it into electrical energy.
Perovskite solar cells have several advantages over traditional silicon-based solar cells, including their flexibility, lightweight, and ease of production. They also have the potential to be much cheaper to produce, making solar power more accessible to a wider range of people. However, perovskite solar cells are still relatively new, and their long-term durability and stability are still being studied.
Despite these challenges, perovskite solar cells have already achieved impressive efficiency levels, with some prototypes achieving over 25% conversion efficiency, which is comparable to some of the most efficient silicon-based solar cells. As research into perovskite solar cells continues, it is expected that their efficiency will continue to improve, making them an increasingly promising technology for renewable energy production.
It is well-known that chemical compounds known as Lewis bases are able to give electrons and bind to uncoordinated lead (Pb) molecules and passivate imperfections in the grain boundary and at interfaces within perovskite film.
With this information the team of researchers applied density functional theory to analyze possible bases that could be bonded to Pb and then identify the most likely one to form strong bonds with Pb.
They found the di-phosphids 1,3-bis(diphenylphosphino)propane, a commercially-available chemical, which did indeed stabilise the perovskite solar cells they were dealing with.
“Phosphine-containing Lewis base molecules with two electron-donating atoms have a strong binding with the perovskite surface,” said Toledo physics professor Yanfa Yan (pictured). “We saw the robust beneficial effects on perovskite film quality and device performance when we treated the perovskite solar cells.”
After stabilisation The cells functioned with a efficiency of 23% for more than 1,500 hours (85degC open-circuit). A 23% efficiency was also recorded for more than 3500 hours at 40degC, at the maximum output, using simulations of AM1.5 illumination.
Next step would be to test similar techniques to construct complete solar panels.
The University of Toledo collaborated with the University of Washington, University of Toronto, Northwestern University and Swiss Federal Laboratories for Materials Science and Technology.
