Theoretical Screening of -NH2-, -OH-, -CH3-, -F-, and -SH-Substituted Porphyrins As Sensitizer Candidates for Dye-Sensitized Solar Cells

Following former Studies, the donor-acceptor combinations of -NH2-substituted porphyrin donor and the acceptors C, D, E, F, H and G, those of -OH-, -CH3- and -Ph-substituted porphyrins as well as porphine donors and the acceptors E, G. and H, and those of -F- and -SH-substituted porphyrin donors and the acceptor G its novel sensitizer candidates have been designed and calculated at the density functional B3LYP level. The result shows that -NH2-, -OH- and -CH3-substituted porphyrins as donors combined with the acceptor G are very promising to provide good performances as sensitizers because of their smaller HOMO-LUMO gaps, much red-shifted absorption bands, and good frontier molecular orbital spatial distributions. They are all promising to challenge the current photon-to-current conversion efficiency record 7.1% of porphyrin-sensitized solar cells in which the -NH2-substituted porphyrins as donors combined with the acceptor G are the best systems.