Synthesis and characterization of novel heteroleptic ruthenium sensitizer for nanocrystalline dye-sensitized solar cells

A novel heteroleptic ruthenium complex of the type [Ru(bpin)(dcbpyH2)Cl]Cl (where bpin is 2,6-bis(pyrazol-1-yl)isonicotinic acid and dcbpyH2 is 4,4′-dicarboxy-2,2′-bipyridine) was synthesized and characterized for tuning the LUMO level of the ruthenium sensitizer to achieve greater stabilization in the excited state which keeps the excess energy to maintain high driving force for electron injection. The photovoltaic performance of this complex as photosensitizer in a nanocrystalline TiO2-based solar cell was studied and its overall energy conversion efficiency was determined (1.9%).