Computational Study of Promising Organic Dyes for High-Performance Sensitized Solar Cells

The energy transition from the ground state to the first excited singlet of four organic dye candidates to be used as sensitizers in solar cells, D5, D7, D9, and D11, has been computationally explored and compared to experimental results with TDDFT (B3LYP, ωB97, and ωB97X functionals) and the CIS(D) and SOS-CIS(D) wave function based methods. The second-order perturbation correction to CI singles’ excitation energies are superior to any TDDFT functional employed here. The performance of SOS-CIS(D) is especially interesting, being in good agreement with absorption spectra and having important computational savings. The best TDDFT results are obtained by the ωB97X functional. Solvation effects on the excitation energies have been studied with three different models, i.e., the Onsager reaction field model, SS(V)PE, and SM8.