Regulating the vertical phase distribution by fullerene-derivative in high performance ternary organic solar cells

Ternary system of PBDB-T:PC71BM:ITIC is systematically investigated by depth-resolved light absorption spectroscopy, GIWAXS, and transient absorption spectroscopy. It is proved that PC71BM can regulate the phase distribution of PBDB-T and ITIC in vertical direction. As a result, the ternary OSC exhibits a best PCE of 11.0% compared to the 9.6% PCE of the binary counterpart.320