How efficient solar cells can be made with non-toxic processes

How efficient solar cells can be made with non-toxic processes
by Robert Schreiber
Berlin, Germany (SPX) Dec 05, 2024

Efforts to produce environmentally friendly and efficient solar cells have taken a significant step forward thanks to a novel design principle developed by researchers at Linkoping University in Sweden. This approach, detailed in a study published in Nature Energy, explores how molecule shapes and interactions influence organic solar cell performance.

"With electrification and the development of AI, we will probably see a significant increase in the world's energy needs. That electricity needs to come from environmentally sustainable sources if we are to slow down climate change at the same time," said Feng Gao, professor of optoelectronics at Linkoping University.

Advancing Organic Solar Cells

Organic solar cells, which use electrically conductive plastics, are emerging as a promising alternative to traditional silicon-based solar cells. These solar cells are not only lightweight and flexible but also relatively inexpensive to manufacture. Their unique properties make them suitable for diverse applications, from wearable electronics to integration into windows or indoor surfaces.

Currently, organic solar cells achieve efficiency levels nearing 20%, comparable to traditional solar technologies. This progress stems from extensive research into the materials' molecular interactions and their influence on performance, known as morphology. However, the manufacturing process still relies heavily on toxic solvents, presenting challenges for scalability and environmental safety.

Pioneering Non-Toxic Production

To address these concerns, Feng Gao's research team, collaborating with experts in China and the United States, has developed a method to produce organic solar cells using environmentally friendly solvents. This advancement paves the way for safer, large-scale production techniques, such as printing.

"To realize mass production of organic solar cells, with printed technologies for example, on a large scale, we need to find methods that don't use toxins. Otherwise, it's not good for the environment or for those working in the factories," Feng Gao explained.

By employing advanced synchrotron X-ray and neutron techniques, the researchers mapped the molecular interactions between the materials and solvents used in manufacturing. This allowed them to establish a design principle compatible with several harmless solvents, and they are optimistic that even water could serve as a solvent in the future.

Toward Sustainable Solar Technologies

The study highlighted the complexity of organic solar cell production, particularly the relationship between morphology and performance. The team investigated the ultra-fast electron movements and nanoscale interactions that underpin charge transport within the material. Understanding these processes marks a critical step toward environmentally sustainable solar technologies.

"Thanks to a toxin-free manufacturing method, we now have a much greater chance of commercializing the technology on a larger scale," Feng Gao concluded.

Research Report:Equally High Efficiencies of Organic Solar Cells Processed from Different Solvents Reveal Key Factors for Morphology Control