Optical and photovoltaic properties of salicylaldimine-based azo ligands

A series of azo dyes containing salicylaldimine-based ligands as side chains were prepared and characterized. Absorption and emission data in five solvents of different polarities were studied. Photoirradiation studies under an oxygen atmosphere in water showed that the Schiff base side chains enhanced the photo-oxidative stability of the azo chromophore. The electrochemical properties of the dyes were investigated by a cyclic voltammetry. The synthesized salicylaldimine-based azo dyes gave two irreversible oxidation potentials. Complexation behavior of synthesized compounds with titanium (IV) ions was illustrated by the change in their absorption spectra. These ligands are appropriate sensitizers for anchoring to the TiO2 surface chemically in dye-sensitized solar cell (DSSC) productions. Electron injection capacities to TiO2 and photovoltaic performance of the synthesized salicylaldimine-based azo dyes were tested with DSSC.