Molecular design of copper complexes as sensitizers for efficient dye-sensitized solar cells

Five new copper complexes with bipyridine ligands and carboxylic acid or methyl ester as anchoring groups have been studied for potential applications in dye-sensitized solar cells. An extensive density functional theory and time dependent DFT study of these sensitizers was performed, investigating the electronic structures and optical properties of the complexes in presence of solvent. Molecular systems showed UV–vis absorptions in the 590–690 nm range; molecular orbitals energy levels meet the requirements for use in DSSC. Our results open the possibility of computationally screening the various predictions on the electronic structure and optical response, thus paving the way to an effective molecular engineering of further enhanced sensitizers for solar cell applications. Interesting work for experimentalists is on the DSSC field.