Impact of Torsion Angles to Tune Efficient Dye-Sensitized Solar Cell/Donor-π-Acceptor Model Containing Triphenylamine: DFT/TD-DFT Study

Abstract

The molecular design of a donor-linker-acceptor based on triphenylamine as a donor group linked with the acceptor cyanoacrylic acid via 2,2'-bithiophene as π-conjugation has been studied for a dye-sensitized solar cell. In this work, the dihedral angle between the donor or the acceptor group and the π-spacer has been rotated. The performance of the molecular design has been investigated computationally, using density functional theory at the B3LYP/6-311G(d,p) theory level, and the effect of tuning torsion angles on the parameters of the solar cells has been studied. To evaluate the effect of tuning torsion angles on photovoltaic properties, the HOMO and LUMO energy levels, optical bandgap energy, oscillator strength, light-harvesting efficiency, excited state lifetime, injection driving force, regeneration driving force, open-circuit voltage, and fill factor have been determined. The results reveal that the molecular design properties that result from the rotation of the dihedral angles can show excellent performance for DSSCs compared to the original dye molecule.