High performance PDI based ternary organic solar cells fabricated with non-halogenated solvent

Most high-performance organic solar cells (OSCs) are so far fabricated using halogenated solvents, which are environmentally hazardous. Therefore, it is imperative to develop high-efficiency OSCs processed by more environmentally friendly solvents. Perylene diimides (PDIs) based acceptors have become one of the most promising candidates for nonfullerene OSCs owing to their outstanding optoelectronic properties. However, PDIs-based ternary OSCs are rarely investigated, let alone the green-solvent processed ones. In this study, non-halogenated solvent processed ternary OSCs using a star-shaped helical perylene diimide (TPDI2) and ITIC as acceptors, PTB7-Th as donor, were fabricated and characterized. The best power conversion efficiency (PCE) of the ternary OSCs were 8.22%, which showed a PCE improvement over 18% comparing to the reference binary blend devices (6.95%). The PCE of 8.22% is among the highest performance reported to date for PDIs-based OSCs devices processed using non-halogenated solvent (without additives).