摘要： The ternary approach using a smaller bandgap acceptor as the near infrared (NIR) absorber to increase the short-circuit current-density (Jsc) usually decreases the open-circuit voltage (Voc). In this contribution, we report a small-molecular acceptor, IN-4F, which has a reduced bandgap and a higher LUMO level than IT-4F, hence, enabling the concurrent increase in the Jsc and Voc when using as the acceptor guest of the host binary of PM6:IT-4F. IN-4F was judiciously designed by fusing benzodithiophene (BDT) and thieno[2′,3′:4,5]thieno to make a larger π?system so as to upshift the LUMO level and reduce the optical bandgap, and meanwhile, by substituting the BDT-4,8 positions with trialkylsilylthiophene chains to downshift the HOMO level to match the deep HOMO of PM6. Again, the structural similarity between IN-4F and IT-4F makes the nanoscaled homogeneous fine film-morphology and the ππ?stacking patterns both well-kept, hence, the fill-factor (FF) well-maintained. The IN-4F based binary solar cell shows 13.1% efficiency and its ternary solar cell blended with IT-4F supplies 14.9% efficiency. Again, the use of IN-4F as the guest acceptor of the PM6:Y6 system enables the increase of Voc due to its higher LUMO level, the increase of Jsc because of the increase of charge mobilities, and the maintenance of FF, affording 16.3% efficiency. This work demonstrates that the π?system extending plus the trialkylsilylthiophene chains substitution can be an effective strategy to synthesize a nonfullerene acceptor guest to realize a ternary material system which enables to increase Voc from its entanglement with Jsc (an issue of the current material approach).