Realization of high performance for PM6:Y6 based organic photovoltaic cells

With advances in material science and a more in-depth understanding of device engineering,the power conversion efficiency(PCE)of solution-processed organic photovoltaic(OPV)cells have significantly boosted in the past few years.In 2019,a high PCE of 15.7%was achieved in the OPV cells adopting a wide bandgap polymer PM6 and a new emerging non-fullerene acceptor Y6.Such outstanding performance has attracted lots of research attention,driving considerable efforts to improve or take advantage of the high-performance PM6:Y6-based system.In this review,we first concentrate on the structural characteristics of PM6 and Y6 with the focus on understanding why their combination for OPV application can obtain such high efficiency.We also update the recent progress in highly efficient PM6:Y6-based OPV cells via various optimizing strategies.Then we summarize the other applications of the PM6:Y6-based system in semi-transparent,flexible or lay e-by-layer devices.The prospects for future OPV studies will be suggested in the end.