Theoretical modifications of the molecular structure of Aurantinidin and Betanidin dyes to improve their efficiency as dye-sensitized solar cells

Two modifications of the molecular structures of Aurantinidin and Betanidin dyes were modeled, and the optical and electrical properties were calculated by using density functional theory (DFT) and time-dependent DFT (TD-DFT). The modification of the structures was done by connecting the units through vinyl groups and using regular electron acceptor and electron donor moieties to the original structures. It has been demonstrated that the modifications improved the electron injection properties of the molecules with higher light-harvesting efficiencies, an increase in the driving force of electron injection (Delta G(inject)), better regeneration energies (Delta G(reg)) and open-circuit photovoltages (V-OC).