Panchromatic photo sensitizers having a Formula of ML1L2X were synthesized, wherein M represents ruthenium atom; X represents a monodentate anion; L1 is heterocyclic bidentate ligand having one of formulae listed below: wherein G2 has one of formulae listed below: and L2 is a tridentate ligand having a formula listed below: Substituents R1, R2, R3 and R4 of L1 are the same or different and are selected from the group consisting of hydrogen, halogens, amino-group alkyl, alkoxy, alkylthio, alkylamino, halogenated alkyl, phenyl and substituted phenyl group. Substituents R5, R6 and R7 of L2 are the same or different and are selected from the group consisting of carboxylic acid and counter anion thereof, sulfonic acid and counter anion thereof, phosphoric acid and counter anion thereof. The above-mentioned photosensitizers are suitable to use as sensitizers for fabrication of high efficiency dye-sensitized solar cell.