Fullerene-free OSCs with higher efficiency, easy process forlarge area devices, and excellent tolerance to the blend film thickness would be the research directions. Among the key factors forbetter performance NFAs, the improvement on charge mobilitystill has much room to play. It is noteworthy that the influenceon device performance of the key factors is interdependent. Aholistic approach should be adopted when we develop newNFAs. Rational molecular design by considering both donorsand acceptors at the same time will further boost photovoltaicperformance of fullerene-free OSCs. We believe fullerene-freeOSCs are expected to achieve PCEs over 15% with Voc >1 V,Jsc >20 mA cm2, and FF > 70% in the near future, through desirable molecular design and optimized device engineering.