Chinese and Canadian researchers have developed an additive that forms covalent bonds with the organic materials in a perovskite solar cell, reducing defects and greatly reducing degradation. Cells treated with the additive retained 98.6% of their original performance after 1,000 hours of testing. Xlynx Materials, a company spun off from the University of Victoria in Canada, is making the material available for later commercial trials.
The cells also performed well in high-temperature testing, retaining 97.6% of their original efficiency after more than 500 hours of exposure at 60°C. In this test, control cells lost 27% of their original performance under the same conditions. The cell processing and testing is fully described in the paper “Covalent Bonding Strategy to Enable Nonvolatile Organic Cation Perovskite for Highly Stable and Efficient Solar Cells” published in Joule.
The researchers used a variety of imaging techniques to understand how their treatment worked and concluded that the polymeric material in the additive, bis-diazirine, formed covalent bonds with the organic element in the perovskite material. “…covalent bonding strategy facilitates ion immobilization, prevents the escape of organic components and eliminates metallic Pb. Thus, it reveals the improved thermal, light fast and electric shock resistant properties of perovskites.
Through further characterization, simulations, and comparison of devices fabricated without treatment, the team was able to observe the operation of the covalent bonding strategy and confirm its role in reducing various unwanted effects that lead to performance degradation in perovskite solar cells as well as side effects. to their original performance by reducing the occurrence of defects. “This work proposes a new and efficient strategy to limit the loss of organic components from perovskites to realize highly efficient and highly stable perovskite solar cells.”
The cells in the study were made by spin-coating, a process commonly used in laboratories but not suitable for large-scale production. However, Xlynx Materials, a company spun off from Canada’s University of Victoria, has begun marketing the treatment under the name BondLynx and is inviting companies aiming to commercialize perovskite solar cells to collaborate on additional projects or purchase the materials for their own use. trials.