US researchers develop new organic solar cell architecture

Scientists from NYU Tandon School of Engineering working on organic solar cell materials was able to improve the performance of a non-fullerene organic solar cell, by utilizing a small molecule of a material known as Squaraine as a crystallizing agent.

“We added a small molecule that functions as an electron donor by itself and enhances the absorption of the active layer,” explains Tandon Associate Professor André D. Taylor. “By adding this small molecule, it facilitates the orientation of the donor-acceptor polymer (called PBDB-T) with the non-fullerene acceptor, ITIC, in a favorable arrangement.”

The cell developed by the team – described in the journal Materials Today, is known as a FRET based solar cell, and utilizes an energy transfer mechanism first observed in natural photosynthesis. Using a new polymer and non-fullerene blend with squaraine as a crystallizing agent the team created a cell which achieved conversion efficiency of more than 10% – something not previously though possible with a single-junction polymer solar cell.

Taylor points out that the cell his team developed is flexible, and could therefore one day be used in a variety of applications including supporting electric vehicles and wearable electronics. “We expect that this crystallizing-agent method will attract attention from chemists and materials scientists affiliated with organic electronics,” says lead author of the paper Yifan Zheng.

Taylor’s research team will now continue to work on improving non-fullerene organic solar cells, as well as working with perovskites.