Over 16% Efficiency of Thick‐Film Organic Photovoltaics with Symmetric and Asymmetric Non‐Fullerene Materials as Alloyed Acceptor

High‐performance organic photovoltaics (OPVs) with relatively thick active layers are essential for large‐scale production. Herein, series of OPVs with different active layer thicknesses are fabricated using PM6 as the donor and BP4T‐4F and BP3T‐4F with symmetric and asymmetric structures as acceptors. With the active layer thickness increasing from 100 to 300 nm, the power conversion efficiency (PCE) of BP3T‐4F‐based binary OPVs is slightly decreased from 15.37% to 14.40%, while the PCEs of BP4T‐4F‐based binary OPVs are markedly decreased from 16.89% to 14.99%. The two kinds of binary OPVs exhibit distinct PCEs and thickness tolerance features, which may be recombined into ternary OPVs using compatible BP3T‐4F and BP4T‐4F as alloyed acceptors. The ternary OPVs exhibit a slightly decreased PCE from 16.91% to 16.03% along with active layer thickness from 100 to 300 nm, benefiting from the well‐optimized phase separation in ternary active layers. It is worth highlighting that the fill factor (FF) of 71.47% is achieved in ternary thick‐film OPVs. The PCE of 16.03% and FF of 71.47% should be among the highest values among OPVs with 300 nm thick active layers.