A thiophene end-capped centrally extended acceptor enables organic solar cells with efficiency over 19.3%

A new small molecule acceptor, CH-TCl, featuring chlorothiophene-based terminal groups and a centrally extended core was synthesized and integrated into ternary organic solar cells. The resulting devices achieved a power conversion efficiency of 19.38%, surpassing the 18.67% of their binary counterparts. The incorporation of CH-TCl as a third component enhanced charge transfer, boosted the open-circuit voltage (VOC), and improved the overall device performance. This study provides an effective strategy for optimizing ternary OSCs by introducing high VOC acceptors.