Heteroleptic, dual tridentate Ru(II) complexes as sensitizers for dye-sensitized solar cells

#1. Field of the Invention

#The present invention relates to solar sensitizers using heteroleptic, dual tridentate Ru(II) complexes and dye-sensitized solar cells, particularly to sensitizers and dye-sensitized solar cells with better conversion efficiency.

#2. Description of the Prior Art

#The foregoing aspects and many of the accompanying advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed descriptions, when taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a diagram illustrating absorption spectra of photosensitizers according to one preferred embodiment of the present invention and the conventional dye; and

#FIG. 2 is a schematic diagram illustrating the structure of a dye-sensitized solar cell according to one embodiment of the present invention.

#Photosensitizers having a formula (1) are provided according to one embodiment of the present invention: RuL1L2  (1) wherein Ru is ruthenium; L1 and L2 are heterocyclic tridentate ligands. L1 is a 2,2′;6′,2″-terpyridine compound and has a formula of (2):

#wherein R1-R3 is selected from the group consisting of hydrogen, a carboxyl group, a salt of a carboxyl group, a sulfonic acid group, a salt of a sulfonic acid group, a phosphoric acid group and a salt of a phosphoric acid group. The cation corresponding to the carboxylate, sulfonate and phosphate includes without limitation to an ammonium ion, a metal ion (such as alkali metal ion) and so on. For example, L1 is represented by the following formulae:

#Preferably, L1 is 4,4′,4″-tricarboxy-2,2′;6′,2″-terpyridine.