A study conducted by scientists from Okinawa Institute of Science and Technology (OIST) Graduate University (Okinawa, Japan) concludes that the leakage of pollutants from perovskite solar cells (PSCs) can be contained by a protective layer of epoxy resin. When added to the surface of a PSC, this “self-healing” polymer can reduce the release of lead into the environment.
PSC-based technologies have considerable potential as a renewable energy source, but their effectiveness is limited by their propensity to release lead, particularly under extreme weather conditions. “While so-called ‘lead-free’ technology is worth exploring, it has not yet achieved efficiency and stability comparable to lead-based approaches,” says the study’s leader, Dr. Yabing Qi. “Finding ways of using lead in PSCs while keeping it from leaking into the environment, therefore, is a crucial step for commercialization.”
With support from OIST’s Technology Development and Innovation Center, Qi and his team tested various coating materials to determine which one would best prevent the leakage of lead in PSCs. The PSCs were exposed to “worst-case” weather simulations, including experiments that mimicked extreme hail and acid rain. Using mass spectroscopy—an analytical technique that measures molecule mass—the research team determined that epoxy resin was significantly more effective in reducing lead leakage.
One key advantage that epoxy resins has over rival encapsulation materials is its ability to reform to its original shape when exposed to sunlight, rainwater and other weather conditions. Qi, who is also head of the Energy Materials and Surface Sciences Unit at OIST, says that epoxy resin is a resilient material but that he and his team are also evaluating other self-healing polymers to see if they offer better encapsulation properties. The OIST research team is also looking to scale up PSCs into perovskite solar panels for commercial use.
The results of the OIST self-healing polymer study was published in Nature Energy.
Source: Okinawa Institute of Science and Technology, www.oist.jp.