Patent ID: 7741559

Claim:
A photoelectric conversion element comprising a composite dye and an n-type semiconductor, said composite dye comprising a plurality of component dyes which have different excitation levels and which are chemically bonded to each other to form a straight chain or branched structure for transferring an excited electron therethrough, wherein said straight chain or branched structure is, at one end thereof, secured to said n-type semiconductor and has, at least at one other end thereof, a free end, wherein, in said straight chain or branched structure, said plurality of component dyes are arranged in an order such that the excitation levels of said plurality of component dyes are decreased as viewed from said one end of said structure toward said at least one other end of said structure, wherein each component dye of said composite dye comprises a metal atom having a ligand coordinated thereto, so that said composite dye is comprised of a multinuclear complex comprising a plurality of metal atoms and a plurality of ligands including at least one bridging ligand, wherein the or each bridging ligand is positioned between mutually adjacent metal atoms in said multinuclear complex to thereby bridge the mutually adjacent metal atoms, wherein the or each bridging ligand in said multinuclear complex comprises a heterocyclic segment having a conjugated double bond and, bonded to said heterocyclic segment, a non-heterocyclic segment, to thereby form an asymmetric structure, wherein the heterocyclic segment is positioned in the or each bridging ligand on a side thereof remote from said n-type semiconductor as compared to the non-heterocyclic segment, wherein a heteroatom in the heterocyclic segment is positioned on a side thereof remote from said n-type semiconductor.