Effects of Side Chains in Third Components on the Performance of Fused-Ring Electron-Acceptor-Based Ternary Organic Solar Cells

We incorporate fused-ring electron acceptor IOIC2 or IOIC5 into the PM6:Y6 blend and investigate the impacts of IOIC2 or IOIC5 on the performance of organic solar cells (OSCs). Both IOIC2 and IOIC5 contain the same fused-ring core but with different side chains (hexyl and hexyloxyl, respectively). The binary devices consisting of the PM6:Y6 blend exhibit a power conversion efficiency (PCE) of 16.3%. The PM6:Y6:IOIC2 ternary OSCs realize a higher PCE of 17.1% benefited from improvement of the open-circuit voltage (VOC) and short-circuit current density (JSC). The PM6:Y6:IOIC5 ternary OSCs achieve a champion PCE of 17.5% with improvement in VOC, JSC, and fill factor. The effects of side chains in the third component on the device performance are studied.