Synthesis and Photo Electrochemical Characterization of an Extended π-Conjugated Heteroleptic Ruthenium (II) Complex

Submit Manuscript | http://medcraveonline.com efficiencies of >10% for metal free dyes, >11% for metal complex and 13% for porphyrin based sensitizers [1-6]. As sensitizers take part in the absorption of solar radiation and injection of electrons into the conduction band of semiconductors, extensive research has been focused on the design of efficient and durable sensitizers. Several dyes have been investigated such as metal complexes, metal-free organic dyes, tetra pyrrolic porphyrin and phthalocyanine based sensitizers [7-16]. Among them, the most successful charge transfer sensitizers are ruthenium based dye molecules, because of their strong and broad metal to ligand charge transfer absorption bands, the stability of their oxidized form and longevity of photo excited states. Grätzel and coworkers have reported >11% efficiency with cis-di(thiocyanato)bis[2,2’-bipyridyl 4,4’-dicarboxylic acid] ruthenium(II)(N3) and trithiocyanato-4,4’4”-tricarboxy-2,2’:6’,2”-terpyridine ruthenium(II) (the black dye) as sensitizers [17]. Many efforts have been made to design the ligands of ruthenium complexes to improve the spectral response to near IR region and device performance.