High open-circuit voltage polymer solar cells based on D-A copolymer of indacenodithiophene and fluorine-substituted benzotriazole

- A D-A copolymer of indacenodithiophene and fluorinated benzotriazole, PIDT-FBTA, was synthesized.
- PIDT-FBTA showed deeper HOMO energy level due to the strong electron-withdrawing difluorine substitution.
- The PSCs based on PIDT-FBTA:PC70BM (1:3) exhibited a high Voc of 0.92 V and a power conversion efficiency of 4.90%.