DFT characterization of the optical and redox properties of natural pigments relevant to dye-sensitized solar cells

Molecular properties of betanidin, betanin and geomphrenin relevant to their role in dye-sensitized solar cells have been studied using DFT and TDDFT at the B3LYP/6-31G(d) level. Ground state geometries, electronic transition energies, oxidation potentials, proton affinities and vibrational-electronic coupling constants are reported.