NOVELTY - A new organic dye contains a 3,4-ethylenedioxythiophene group and thiophene groups.    USE - The organic dye is used in a dye sensitization photoelectric conversion element, which is used in a dye-sensitized solar cell (all claimed).    ADVANTAGE - The dye provides a dye-sensitized solar cell with better molar absorptivity, short-circuit photocurrent density (Jsc) and photoelectric conversion efficiency. The cell enables refining without using an expensive column, thus significantly reducing cost of synthesis of dyes.    DETAILED DESCRIPTION - The organic dye of formula (1) is new.    R1 = =C(CN)COOH or =C(X)C(Y)=C(CN)COOH;    X, Y = hydrogen or 1-6C alkyl;    R2-R5 = hydrogen, (un)substituted 1-30C alkyl or 1-30C alkoxy;    Ar = 6-30C aryl or 6-50C heteroaryl optionally substituted 1-30C alkyl, aryl, 1-30C alkoxy, halogen, amide, cyano, hydroxyl, nitro, or acyl; and    Z, Z' = 1-6C alkyl;    n = 1-10; and    m, m1 = 0-5, and both are not simultaneously 0.    INDEPENDENT CLAIMS are included for:    (a) manufacture of the organic dye of formula (1-1) by manufacturing the compound of formula (4) by reacting the compounds of formula (2) and formula (3), manufacturing the compound of formula (5) by reacting the compounds of formula (2) and formula (4) with POCl3 in organic solvent, and reacting the compound of formula (5) with cyanoacetic acid or XCCH2C(Y)=C(CN)COOH in methyl cyanide in the presence of piperidine;    (b) manufacture of the organic dye of formula (1-2) by manufacturing the compound of formula (4) by reacting the compounds of formula (2) and formula (3), manufacturing the compound formula (7) by reacting the compound of formula (4) with the N-bromostyrene in organic solvent, manufacturing the compound of formula (9) by reacting the compound of formula (7) with the compound of formula (8), manufacturing the compound of formula (10) by reacting the compound of formula (9) with POCl3 in organic solvent, and reacting the compound of formula (10) with cyanoacetic acid or XCCH2C(Y)=C(CN)COOH in methyl cyanide in the presence of piperidine; and    (c) a dye sensitization photoelectric conversion element including oxide semiconductor corpuscles impregnated with the organic dye;    (d) a dye-sensitized solar cell including the dye sensitization photoelectric conversion element.    a =1-5.