Structures and spectroscopic properties of ruthenium phenanthroline solar-cell sensitizers: A computational study

The density functional theory (DFT) was applied to fully optimize the ground- and excited-state structures of six ruthenium photosensitizers with 0–4 carboxyls coordinating phenanthroline ligands. The electronic spectra in solution were calculated by the time-dependent DFT (TD-DFT) method. The results showed that all the carboxylic sensitizers are good candidates for dye-sensitized solar cell because of their intense and wide absorption bands in the visible region. Varying carboxyl groups of the sensitizers slightly changes the absorption spectra, but the number and substituted position of these anchors strongly improve the electron-accepted ability of their situated phenanthrolines.