F-M is a non-fullerene acceptor th at absorbs visible light, when used in a front cell paired with NIR absorbing rear cell, the resulted tandem organic solar cell gave a record energy conversion efficiency of 17.3%. Tandem Cell Device performance: ITO/ZnO/PFN-Br/PBDB-T:F-M/M-PEDOT/ZnO/PTB7- Th:O6T-4F:PC71BM/MoO3/Ag Voc=1.642 V Jsc=14.35 mA/cm2 FF=73.7% PCE=17.3%
