Simple-structured small molecule acceptors constructed by a weakly electron-deficient thiazolothiazole core for high-efficiency non-fullerene organic solar cells

A novel strategy is proposed to construct simple-structured SMAs using a weakly electron-deficient thiazolothiazole (TTz) core. The highest PCE of 8.77% is recorded for TTz1-based OSCs, which is the highest efficiency to date among non-fullerene OSCs with simple-structured SMAs.