A simple fluorene core-based non-fullerene acceptor for high performance organic solar cells.

A small molecule non-fullerene acceptor based on a fluorene core having a furan π-spacer and end capped with rhodanine (FRd2) is developed for solution processable bulk heterojunction organic solar cells (OSCs). The simplistic synthetic protocol reduces several reaction steps and hence production cost. Extended π-conjugation via furan units and the presence of electronegative rhodanine groups result in a power conversion efficiency of 9.4% in OSCs, which is the highest so far among these categories of molecules.