Computational experiments on semiconducting polymers point to promising new direction for solar cell research

Organic solar cells are ideal for use in flexible electronics because of the inherently malleable nature of semiconducting polymers. Recent research on the interplay between processing, thermodynamics, and mechanical stability of typical photoactive layers in organic cells is providing a deeper understanding of these high-potential materials.

Ganesh Balasubramanian, P.C. Rossin Assistant Professor of Mechanical Engineering and Mechanics, and his graduate student Joydeep Munshi recently set out to understand how stable these materials are when deformed, and whether the promising properties can be realized under harsh loading conditions when the solar cells may be subject to stretching and compression. Through computational experiments using the leadership class computing resources in Frontera, the team demonstrated that adding small molecules to the semiconducting polymer blend enhances the performance and stability of material used in organic solar cells. They predict this is also true for organic solar cell material more generally. 

The study is described in an article, “Elasto-morphology of P3HT:PCBM bulk heterojunction organic solar cells” featured on the back cover of Soft Matter. Additional authors include: professors TeYu Chien at the University of Wyoming and Wei Chen at Northwestern University.

“Based on previous literature, we anticipated that variations in the materials processing parameters would influence the structure as well as the thermal and mechanical properties of these solar cells,” says Balasubramanian. “However, the finding that presence of small molecular additives can augment the mechanical properties is new knowledge gained from this work.”

The team demonstrated that, in addition to the solar-to-electrical power conversion efficiency, the mechanical stability and flexibility of typical organic solar cells is significantly impacted by the presence of molecular additives. 

“This could prove crucial towards the commercialization of organic solar cells,” says Balasubramanian. 

Read the full story in the Lehigh University News Center

Ganesh Balasubramanian

Ganesh Balasubramanian, P.C. Rossin Assistant Professor, Mechanical Engineering and Mechanics

Despite the recent advances in the power conversion efficiency of organic solar cells, an insight into the processing-driven thermo-mechanical stability of bulk heterojunction active layers is still warranted.

(Illustration Credit: Department of Mechanical Engineering and Mechanics/Lehigh University)