Fused Nonacyclic Electron Acceptors for Efficient Polymer Solar Cells

We design and synthesize four fused-ring electron acceptors based on 6,6,12,12-tetrakis(4-hexylphenyl)-indacenobis(dithieno[3,2-b;2′,3′-d]thiophene) as the electron-rich unit and 1,1-dicyanomethylene-3-indanones with 0–2 fluorine substituents as the electron-deficient units. These four molecules exhibit broad (550–850 nm) and strong absorption with high extinction coefficients of (2.1–2.5) × 105 M–1 cm–1. Fluorine substitution downshifts the LUMO energy level, red-shifts the absorption spectrum, and enhances electron mobility. The polymer solar cells based on the fluorinated electron acceptors exhibit power conversion efficiencies as high as 11.5%, much higher than that of their nonfluorinated counterpart…

• NN
  National Natural Science Foundation of China

  Award: 91433114
• MO
  Ministry of Science and Technology of the People's Republic of China

  Award: 2013CB834702
• RG
  Research Grants Council, University Grants Committee

  Award: 14303314
• CU
  Chinese University of Hong Kong

  Award: 4053128
• OO
  Office of Naval Research

  Award: N000141410221
• DO
  Division of Materials Research

  Award: DMR-1507249