Structural and Spectral Properties of 1,2-dihydroxy-9,10-anthraquinone Dye Sensitizer for Solar Cell Applications

The geometries, electronic structures, polanzabilities, and hyperpolarizabilities of natural dye sensitizer alizarin from madder fruit was studied based on density functional theory using the hybrid functional B3LYP. Features of the electronic absorption spectra in the visible and near-UV regions were assigned based on time-dependent density function theory calculations. The calculated results suggest three excited states with the lowest excited energies in 1,2-dihydroxy-9,10-anthraquinone and it was due to photoinduced electron transfer processes. The interfacial electron transfer between semiconductor TiO2 electrode and dye sensitizer 1,2-dihydroxy-9,10-anthraquinone is due to an electron injection process from excited dye to the semiconductor conduction band. The importance of hydroxyl group in geometries, electronic structures and spectral properties were reported.