New dithienosilole- and dithienogermole-based BODIPY for solar cell applications

Abstract

We report two efficient donor materials for organic solar cells, namely Si-BDP and Ge-BDP, composed by the novel union of thienyl Bodipy wings and a dithienosilole/dithienogermole core. These new donor molecules exhibited excellent solubility in organic solvents, extended π-conjugation and low-lying energy levels that matched with fullerene acceptors, supporting their application as donors in OSCs. Under optimized conditions and using PC70BM as an acceptor, desirable PCEs of 4.58% and 4.12% were observed for Si-BDP and Ge-BDP, respectively.