LAUSR

Abstract A1-D-A2-D-A1 type of structured BT-CMCN, which consists of an electron-deficient benzothiadiazole (BT) (A2), electron-rich thiophene (D) and electron-deficient dicyanomethylene-4H-chromene (CMCN) (A1) moiety, was synthesized. BT-CMCN showed pretty good thermal stability with the onset of decomposition temperatures of 304 °C at 5 wt % loss. The optical and electrochemical properties were investigated that reveal the HOMO/LUMO energy levels of BT-CMCN are −5.29 eV/−3.58 eV with the optical band gap of 1.72 eV. The HOMO/LUMO energy levels of BT-CMCN are higher than those of PC71BM. The best performance based on BT-CMCN/PC71BM in inverted-type organic solar cells (OSCs) exhibits the PCE of 0.69% with a short-circuit current density (Jsc) of 2.03 mA/cm2, Voc of 0.79 V, and fill factor (FF) of 42.7%.