Molecular Engineering of Indacenodifuran-Based Non-Fullerene Acceptors for Efficient Organic Solar Cells

Energy-efficient non-fullerene acceptors attracting great attention for developing efficient organic solar cells (OSCs). Though many materials have been developed to improve the optical and optoelectronic characteristics of OSCs, the search continues to strengthen this field further. Therefore, herein, we designed an environmentally-benign indacenodifuran-based electron acceptor molecules (MH1-MH8) by substituting various end-capped electron-withdrawing moieties (COOH, SO3H, NO2, and CN). The open-circuit-voltages, binding energy, transition energy, transition density analysis, and electron and hole reorganization energies for MH1–MH8 were computed for these materials. These designed materials MH1-MH8 have better photovoltaic, photophysical, and electrical properties than R due to their narrower bandgap (1.91 eV), higher absorption (725.56 and 785.46 nm in gas and chloroform), low-mobility of electrons (0.0033) and holes (0.0019), and lower binding energy of 0.20 eV). We have also performed a charge transfer study by establishing a donor:acceptor complex MH2:PTB7-TH, showing a great charge transformation at the donor:acceptor interface. Thus, the designed compounds (MH1-MH8) with excellent optoelectronic properties could be considered a promising and environmentally friendly option to create compelling organic solar cells.