摘要： Fused-ring electron acceptors (FREAs) based ternary organic solar cells (OSCs) have made significant progress and attracted considerable attention due to their simple device architecture and broad absorption range in devices. There are three key parameters that need to be fine-tuned in ternary OSCs including absorption, energy level and morphology in order to realize high efficiencies. Herein, a series of FREAs with diverse electron-rich cores or electron-deficient terminals are developed and rationally combined to achieve high performance ternary OSCs. A new factor of dipole moment of FREAs’ terminals is unveiled and its working mechanism has been thoroughly investigated by systematical studying of six ternary OSCs. These ternary blends all exhibit complementary absorptions and cascade energy levels, which can facilitate efficient light-harvesting and charge transfer. Additionally, the morphological effects on ternary OSCs are eliminated through comparative studies while demonstrating distinctively different performance. The preliminary results show that compatible dipole moment between two FREAs is critical in ternary blends. Specifically, the performance of the ternary system with two FREAs having quite different dipole moment terminals is worse than that with similar terminal dipole moments. The pair with larger difference in dipole moment will also negatively impact device performance. This interesting phenomenon is likely due to that very different dipole moments of terminals in FREAs can significantly decrease the electron mobility as well as induce unbalanced hole/electron transport. Consequently, it results in increased charge recombination and reduced charge collection efficiency. This finding demonstrates that dipole moment of FREAs should be taken into account in designing ternary OSCs.