RESUMO
Ruthenium-based metal complex dyes have been employed extensively in dye-sensitized solar cells (DSSCs) as photosensitizers, but the cost and toxicity of metal complexes have promoted the development of metal-free organic dyes. The present investigation deals with the synthesis of hemicyanine and Dicyanoisophorone (DCI) based dyes adopting the D-π-A strategy, and their application on sensitization of nano-crystalline ZnO electrodes by appending the carboxyl (COOH) anchoring group as a pendant on the primary skeleton of dyes. Dyes have been characterized by UV, FTIR, and NMR spectroscopic studies. Absorption maxima (λmax) were found in the region 416-551 nm while emission wavelength (λem) was observed in the range 575-685 nm. Cyclic voltammetry and DFT calculations were used to estimate redox potential and band gap energies of dyes.
