Patent ID: 8759521

Claim:
Photosensitizers having a chemical formula represented by Formula (a): ML 1 L 2 X, Formula (a) wherein M represents ruthenium atom; X represents a monodentate anion; L 1 represents a heterocyclic bidentate ligand having a structural formula represented by Formula (b) or Formula (c) listed below: wherein G 1 is a 5-membered nitrogenous ring and has a structural formula represented by a member selected from the group consisting of Formula (d), Formula (e), Formula (f) and Formula (g) listed below: wherein G 2 has a structural formula represented by Formula (h), Formula (I) or Formula (j) listed below: and L 2 represents a tridentate ligand having a structural formula represented by Formula (k) listed below: wherein substituents R 1 , R 2 , R 3 and R 4 of L 1 are the same or different and are selected from the group consisting of hydrogen, halogen, amino-group alkyl, alkoxy, alkylthio, alkylamino, halogenated alkyl, phenyl and substituted phenyl group, and substituents R 5 , R 6 and R 7 of L 2 are the same or different and are selected from the group consisting of hydrogen, carboxylic acid, carboxylate, sulfonic acid, sulfonate, phosphoric acid and phosphate.