NOVELTY - An organic polyelectrocyclic dye is new.    USE - New organic polyelectrocyclic dye for a dye sensitized solar cell (claimed).    ADVANTAGE - Achieves 5% photoelectric conversion efficiency, has excellent photothermal stability, can be easily synthesized, uses inexpensive reaction material and can be easily purified.    DETAILED DESCRIPTION - An organic polyelectrocyclic dye of formula (I) is new.    R1, R2=H, hydrocarbyl or OH;    R3-R6=H, halo, hydrocarboxyl, hydrocarbylthio or their derivatives;    R7-R9=multi-heterocycle or its derivative;    A=CN, acetyl, aldehydyl, carboxyl, amide, halogenated carbon, NO2, sulfonic group or aryl; and    B=carboxyl, sulfonic acid, orthophosphorous acid, hypophosphorous acid, OH, peroxycarboxylic acid, amide, boric acid and square acid.    An INDEPENDENT CLAIM is included for a dye-sensitized solar cell comprising conductive layer, light absorption layer, reduction layer and counter electrode connected sequentially between two transparent substrate layers. The light absorption layer is composed of semiconductor nanoparticle layer and dye layer which contains the organic polyelectrocyclic dye. The transparent substrate layers are glass substrate or plastic such as polyethylene glycol terephthalate, polyethylene naphthalene, polycarbonate, polypropylene, polyimide or cellulose triacetate. The conductive layer is composed of tin indium oxide, fluorine indium oxide, zinc oxide-gallium oxide, zinc oxide-aluminum oxide, tin oxide or zinc oxide. The semiconductor nanoparticle is silicon, titanium dioxide, stannic oxide, zinc oxide, tungsten oxide, niobium oxide and tiraium strontium oxide and has average particle diameter of 0-50 nm. The electrolyte layer is composed of iodine/iodide electrolyte, ionic liquid and organic or inorganic hollow transmission material. The ionic liquid contains anion of formula I-, Br-, Cl-, (N(CN)2)-, ((SO2CF3)2)-, (PF6)-, (BF4)-, (NO3)-, (C(CN)3)-, (B(CN)4)-, (CF3COO)-, (ClO4)-, (BF3CF3)-, (CF3SO3)-, (CF3CF2SO3)-, (CH3H2SO3)-, ((CF3SO2)2N)-, ((C2H5SO2)2N)-, ((CF3SO2)3C)-, ((C2F5O2)3C)-, ((FSO2)3C)-, (CH3CH2OSO3)-, (CF3COO)-, (CF3CF2COO)-, (CH3CH2COO), (CH3COO)-, (P(C2H5)3F3)-, (P(CF3)3F3)-, (P(C2H5)(CF3)2F3)-, (P(CH2CF3)3F3)-, (P(C2F5)3F3)-, (P(C2F5)(CF3)F5)-, (P(CF3)3F3)-, (P(C6H5)3F)-, (P(CH3)3)-, (P(C4H9)3F)-, (P(C2H5)2F4)-, ((C2H5)2P(O)O)-, ((C2H5)2P(O)O5)2-, (PC6H5)2F)-, ((CF3)aP(O)O)-, ((CH3)2PO)-, ((C4H9)2P(O)O)-, (CF3P(O)O2)2-, (CH3P(O)O2)2-, ((CH3O)2P(O)O)-, (BF2C2F5)2)-, (BF3(CF3))-, (BF2(CF3))-, (B(C2F5)4)-, (BF3(CN))-(BF2(CN)2)-, (B(CF3)4)-, (B(OCH3)4)-, (B(OCH3)2(C2H5))-, (B(O2C2H2)2)-, (B(O2CH2)-, (N(CF3)2)-, (AlCl4)- and (SiF6)-. The organic hollow transmission material is 2,2',7,7'-tetra-bi(N,N-di-o-methoxyaniline)-9,9'-spirobifluorene or organic P-type semiconductor. The counter electrode is composed of platinum, gold, nickel, copper, silver, indium, ruthenium, palladium, rhodium, iridium, osmium, carbon or conductive polymer such as polyaniline, polypyrrole, polythiophene, poly-p-phenylene vinylene and polyether.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the dye sensitized solar cell.    Transparent substrate layers (1)    Conductive layer (2)    Light absorption layer (3)    Reduction layer (6)    Counter electrode (7)