Theoretical Studies on the Absorption Spectra of β-Diketonato Ruthenium Tricarboxyterpyridyl Dyes

The absorption spectra of five β-diketonato ruthenium tricarboxyterpyridyl dyes in ethanol have been calculated by the Time Dependent Density Functional Theory, and studied by the Transition-Component Analysis (TCA). The computed absorption spectra well reproduced the experimental ones based on the shape for the entire visible light range. The TCA quantitatively explained the contents of the absorption spectrum in detail, and, by comparing to the results for Black Dye, found that the β-diketonato ligands, by enhancing the electron donor ability, could contribute to the absorption spectra in the longer wavelength region, and made the β-diketonato ruthenium tricarboxyterpyridyl dyes work well as photo-sensitizers in dye-sensitized solar cells.