Breakthrough Achieved in Production of Key Component of Solar Technology

Breakthrough Achieved in Production of Key Component of Solar Technology

August 21, 2024 | By Dave DeFusco

UNC researchers have made a significant breakthrough in the production of electronic acceptors, a key component of organic solar cells to make solar energy more accessible and affordable, according to the paper, “A General and Mild Synthetic Method for Fused-Ring Electronic Acceptors,” in Science Advances.

Organic solar cells are a type of solar technology that use carbon-based compounds to convert sunlight into electricity. These cells are lightweight and flexible, and can be produced in various forms, making them an attractive alternative to traditional silicon-based solar panels.

At the heart of this advancement are molecules known as Fused Ring Electron Acceptors (FREA), which play a crucial role in capturing and converting sunlight into electrical energy within organic solar cells. Despite their potential, the production of FREAs has been challenging, involving complex processes, low yields and high costs. However, UNC researchers have developed new, streamlined methods to simplify the production of these vital materials.

“Traditional methods of producing FREAs have been fraught with difficulties,” said Xiaowei Zhong, the first author of the paper and a graduate research assistant in the Department of Chemistry at UNC.

One of the main hurdles in the production of FREAs has been the need to fuse different aromatic (ring-shaped) molecules together through a single atom, such as carbon or nitrogen. This fused-ring structure is critical for the proper functioning of the FREA molecules in solar cells, but achieving it has been difficult and inefficient with existing techniques.

The research team tackled these challenges by introducing three key innovations. The first involved a new method to fuse aromatic units using carbon atoms. The researchers discovered that by using specific catalysts—substances that speed up chemical reactions—they could make this process much more efficient. This method allows for greater flexibility in designing FREAs with different chemical structures, which could lead to better-performing solar cells.

The second innovation focused on fusing aromatic units with nitrogen atoms. The team developed a method that uses a different catalyst to achieve this fusion at lower temperatures, resulting in higher yields and fewer byproducts. This advancement simplifies the process and reduces costs.

The final step in producing FREAs involved linking the fused-ring core part with the ends for better light capture and electrical charge transfer. Traditionally, this step has been cumbersome, but the researchers identified a new catalyst that makes the process faster and more efficient, with higher yields and easier separation of the final product.

“These innovations could have a significant impact on the future of organic solar cells,” said Wei You, senior author of the paper and professor of chemistry. “By making it easier and cheaper to produce FREAs, the overall cost of organic solar cells could be greatly reduced. This, in turn, could lead to more widespread adoption of organic solar cells, especially in applications where traditional solar panels are less practical.”

In addition to reducing costs, these new methods expand the possibilities for designing and improving organic solar cells. With the ability to create a wider range of FREAs, researchers can explore new designs that might be even more efficient at converting sunlight into electricity.

“This breakthrough represents a major step forward in the quest for more sustainable and accessible solar energy solutions,” said Dr. You. “As the world continues to seek alternatives to fossil fuels, advancements like these will be crucial in driving the transition to a greener, more energy-efficient future.”