Density functional theory study on the electronic structure of Monascus dyes as photosensitizer for dye-sensitized solar cells

This work presents a theoretical study of electronic and redox properties of Monascus dyes using DFT and TDDFT with B3LYP/6-31+G(d,p) level. The dye properties in solvent environment were carried out with IEF-PCM(UAKS)/TDDFT/B3LYP/6-31+G(d,p) method. The ground and excited state oxidation potentials as well as electron injection from the dyes to semiconductor TiO2 are reported. The calculation shows that all of the dyes can potentially be good photosensitizers in DSSC. Their LUMOs lie over the Ecb of TiO2 and their HOMOs lie under the reduction potential energy of the electrolytes ( I − / I 3 − ) corresponding to ability of electron transfer from the dye excited state to TiO2 and charge regeneration after photooxidation process, respectively.