Researchers from China's Fudan University, Central South University, East China Normal University, Chinese Academy of Sciences and Suzhou University of Science and Technology, along with Canada's University of Victoria and Austria's University of Vienna, have proposed a novel strategy to achieve efficient and stable perovskite solar cells (PSCs) through introducing bis-diazirine molecules to immobilize the organic cations by covalent bonds.
The resulting PSCs exhibited a high certified efficiency of over 24% with long operational stability of over 1,000 hours. The scientists believe that this strategy also possesses great potential in other perovskite-based optoelectronic devices.
The team's strategy was based on the use of a new adhesive to protect perovskites. It’s called BondLynx, and it was originally produced by Canadian materials company XlynX for other purposes before being tested on solar cells.
BondLynx is a crosslinker that forms chemical covalent bonds with organic components, preventing them from getting loose and reducing efficiency.
The team treated perovskite solar cells with BondLynx, and then exposed them to long-term heat and light to see how they performed compared to solar cells that hadn’t been treated. The solar cells started with an efficiency of 24%, and retained almost 99% of this after 1,000 hours of continuous exposure to simulated sunlight. By comparison, untreated solar cells lost 35% of their original efficiency under the same conditions over the same time frame.
The solar cells were also exposed to a constant heat of 60 °C (140 °F) for 600 hours. The BondLynx-treated ones managed to hang onto almost 98% of their efficiency over that time, while the control group lost 27% of theirs.