DFT study of anthocyanidin and anthocyanin pigments for Dye-Sensitized Solar Cells: Electron injecting from the excited states and adsorption onto TiO2 (anatase) surface

Abstract

We explored, the absorption spectra, excited states and electronic injection parameters of anthocyanidin and anthocyanin pigments using the level of theory (TD)CAM-B3LYP/6-31+G(d,p). For the most isolated dyes, the distribution pattern of HOMO and LUMO spreads over the whole molecules, which lead an efficient electronic delocalization. The calculated light harvesting efficiencies (LHEs) are all near unity. Methoxy group in peonidin molecule lead the largest oscillator strength and LHE. The presence of water lead a higher spontaneous electronic inject process, with ΔGinject average of -1.14 eV. The ΔGinject order is peonidin < delphinidin < cyanin