biostudies-literatureXia HResearch Grants Council of Hong KongRGC Senior Research Fellowship SchemeHong Kong Polytechnic UniversityChangzhou Social Development ProjectNational Natural Science Foundation of ChinaSeed Plan" Project of China Petroleum and Chemical CorporationJiangsu Provincial Talents Project of High-Level Innovation and Entrepreneurshipe2501428https://www.ebi.ac.uk/biostudies/studies/S-EPMC12447044biostudies-literatureUnknown37(37)In organic solar cells (OSCs), the ternary strategy is a mainstream approach to obtaining highly efficient OSCs. A deeper understanding of working mechanisms and the material selection criteria for boosting open-circuit voltage (V_OC) is essential for further OSC breakthrough. Through a modular design principle, a series of oligomeric donors - 5BDD, 5BDD-F, 5BDT-F, and 5BDT-Cl - with similar molecular configurations but varying HOMO levels is systematically designed. These findings reveal that the HOMO levels of these oligomers have a negligible impact on the V_OC of the ternary OSCs. Instead, their excellent compatibility with acceptors played a pivotal role in enhancing V_OC. The oligomers effectively suppressed excessive acceptor aggregation and achieved AgAdvanced materials (Deerfield Beach, Fla.)Unveiling Energy Loss Mechanisms to Empower Ternary Organic Solar Cells with over 20% Efficiency: A Systematic Oligomeric Approach.PMC12447044C7018-20GQ-CDBK22329822275024C4005-22Y8-8480SRFS2223-5S01Q-CD7X51673031CZ20220027Liu HLi GXia HMa RLu XYou CFu JZhu WLang YLuo DfalseUnveiling Energy Loss Mechanisms to Empower Ternary Organic Solar Cells with over 20% Efficiency: A Systematic Oligomeric Approach.In organic solar cells (OSCs), the ternary strategy is a mainstream approach to obtaining highly efficient OSCs. A deeper understanding of working mechanisms and the material selection criteria for boosting open-circuit voltage (V_OC) is essential for further OSC breakthrough. Through a modular design principle, a series of oligomeric donors - 5BDD, 5BDD-F, 5BDT-F, and 5BDT-Cl - with similar molecular configurations but varying HOMO levels is systematically designed. These findings reveal that the HOMO levels of these oligomers have a negligible impact on the V_OC of the ternary OSCs. Instead, their excellent compatibility with acceptors played a pivotal role in enhancing V_OC. The oligomers effectively suppressed excessive acceptor aggregation and achieved Ag2025-01-01T00:00:00Z2025 Sep2026-06-03T15:14:38.282Z2026-04-29T03:08:59.438ZS-EPMC124470444057441910.1002/adma.202501428