The main obstacle to the pursuit of high efficiency in organic photovoltaics is the large open circuit voltage (V_oc) loss. To address this issue, the team constructed a ternary OPVs (TOPVs) consisting of symmetric-asymmetric receptors and demonstrated it to be a viable approach through a test system.

　　Joule (IF 41.248) published a study in February 2022. The research team composed symmetric BTP-eC9 and asymmetric BTP-S9 receptors with similar absorption curves to form ternary OPVs (ternary OPVs, TOPVs). Through experiments, the research team demonstrated that increasing V_oc could reduce energy disorder and nonradiative decay.

　　Through the testing of instruments such as quantum yield measurement systems, the research results showed that compared with binary OPV, TOPV required higher voltage without sacrificing the absorption range. In addition, because π-π stacking was stronger than binary thin films, the ternary blends exhibited stronger charge transport properties and thus improved fill factor (FF).

　　The TOPV studied in this paper exhibited an efficiency of 18.8% (certified as 18.7%) with a voltage of 0.861 V and FF of 79.34%. This is the highest value among certified single-junction OPVs to date and paves the way for efficient OPV.