A nonvolatile morphology regulator for enhancing the molecular order in the active layer and power conversion efficiency of polymer solar cells

Herein, we propose a novel concept of adding PDI–PC61BM as a non-volatile morphology regulator to the active layer, with the low bandgap polymer PBDB-T as a donor and IT-DM as a nonfullerene molecule acceptor, to promote the molecular order of both the donor and acceptor. The power conversion efficiency (PCE) of the device based on PBDB-T:IT-DM system is promoted by 1.39% from 10.63% to 12.23%.