NOVELTY - An optoelectric transducer contains an oxide semiconductor microparticle sensitized by methine-group pigment (I), some of which are new.    USE - For solar cell (claimed).    ADVANTAGE - The optoelectric transducer has excellent electroconductivity, high conversion efficiency and high practicability.    DETAILED DESCRIPTION - The optoelectric transducer contains an oxide semiconductor microparticle sensitized by methine-group pigment of formula (I).    ring a = benzene ring optionally substituted by aromatic residue, which is optionally substituted by aliphatic hydrocarbon residue or substituent having halogen atom, amide, hydroxyl, cyano, nitro, alkoxyl, acyl or optionally substituted amino group;    R1, R2 = aliphatic hydrocarbon residue or acyl group having H, optionally substituted aromatic residue or other substituents, and R1 and R2 may form optionally substituted ring, which is bonded with ring a;    X = optionally substituted aromatic residue, cyano, phosphoric acid, sulfonic acid, carboxyl, carbonamide, alkoxycarbonyl or acyl group;    A1, A2 = H, optionally substituted aromatic residue, hydroxyl, phosphoric acid, cyano, halogen, optionally substituted aliphatic hydrocarbon residue, carboxyl, carbonamide, alkoxycarbonyl or acyl group;    Y = sulfur, selenium, tellurium, CR3R4 or NR5;    R3, R4 = aromatic residue optionally substituted by aliphatic hydrocarbon residue or substituent having H, halogen atom, amide, hydroxyl, cyano, nitro, alkoxyl, acyl or optionally substituted amino group;    R5 = optionally substituted aromatic residue, optionally substituted aliphatic hydrocarbon residue or acyl group having H;    ring b = ring optionally substituted by aromatic residue, which is optionally substituted by aliphatic hydrocarbon residue or substituent having halogen atom, alkoxyl or acyl group;    m = 0-7; and    n = 1-7.    When n is 2 or more, then several A1 and A2 may form optionally substituted ring having substituents chosen from A2 and X1. INDEPENDENT CLAIMS are included for the following:    (1) manufacture of optoelectric transducer, which involves forming oxide semiconductor microparticle supported by pigment of formula (I) in the shape of a thin film;    (2) solar cell, which uses the optoelectric transducer;    (3) new compounds of formula (I) where R1 and R2 = benzene; Y = S; m = 1 or 2; n = 1 and either (a) X = carboxyl , A1 = H and A2 = cyano or (b) X, A1 and A2 = rhodanine ring;    (4) new compounds of formula (III) where R11 and R12 an (un)substituted amino group or a substituent; m3 = 0-3; n3 = 1 or 2; X3 = carboxyl group; A5 = H; and A6 = cyano.