“…The optimal PM6:Y6 binary device exhibits a V oc of 0.84 V, a J sc of 24.25 mA cm −2 , and an FF of 0.795, yielding a PCE of 16.19%, in line with previous report. [11,26] By contrast, the binary device based on DRTB-T-C4:Y6 has a poor PCE of 4.14% with a V oc of 0.90 V, a J sc of 10.93 mA cm −2 , and an FF of 0.42. When increasing the content of DRTB-T-C4 by 10% (in donors w/w) into the host PM6:Y6 blend, the resulting ternary device produces the PCE of 17.13%, accompanied with a V oc of 0.85 V, a J sc of 24.79 mA cm −2 , and an FF of 0.813, which is one of the best efficiencies for the ternary OSCs reported to date.…”