TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The oxide semiconductor fine particles are made of titanium dioxide, tin dioxide, tungsten trioxide, zinc oxide, niobium oxide, iron oxide, zirconium oxide, magnesium oxide, cadmium sulfide, zinc sulfide, lead sulfide, bismuth sulfide, cadmium selenide, and/or cadmium telluride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The porous film can also be sensitized with the dye and additional dyes. The additional dyes are metal complex and/or organic dye. The organic dye is indoline, coumarin, cyanine, merocyanine, hemicyanine, methin, azo, quinone, quinonimine, diketo-pyrrolo-pyrrole, quinacridone, squaraine, triphenylmethane, perylene, indigo, xanthene, eosin, and/or rhodamine. The dye is adsorbed together with an additive. The additive is a co-adsorbent, preferably a steroid, crown ether, a cyclodextrin, a calixarene, and/or polyethyleneoxide. Preferred Definitions:    A=group of formula (V');    A'=quinolyl-G or pyridyl-G;    G=-R28-COOH;    D=group of formula (III)R1=H or D;    R'2=H or -C(R5)R6;    R3=H;    R4=group of -C(R5)R6;    R5=O;    R6=NR7R10, NHR7, OR7, N(1-8C alkyl)-O-(1-8C alkyl);    R7, R10=(fluorinated) 1-14C alkyl, benzyl, 3-14C heteroaryl, or 6-20C aryl where alkyl can be substituted by N(1-8C alkyl)2, the heteroaryl can be substituted by CO-O-1-8C alkyl or 1-8C alkyl, the benzyl and aryl can be substituted by fluorine, 1-8C alkyl, fluorinated 1-4C alkyl, O-1-8C alkyl, or N-(1-8C alkyl)2, or the aryl can be substituted by Cl, CO-1-8C alkyl, -CN, fluorinated (1-4C alkyl), or fluorinated O-(1-4C alkyl);or    R7=6C arylene;or    R21=group of formula (IA);    R15=H, OR25 or OCOR25;    R17=(1-8C alkyl);    R29=G or group of -C(R5)R6;or    R17 and R20=form together with N-atom R17 and R18 are attached to N-(CH2)2-, N-CH2-C(CH3)2-, cyclobutyl amine, cyclohexyl amine, phenyl amine, isopropyl phenylamine, N-(CH2)2-O-, N-oxyphenyl, 9-methylene fluorenyl thiophenylamine, or N-(CH2)2-S-;    R18=1-8C alkyl, 8-20C aralkenyl, 6-24C heteroaryl, or 6-20C aryl where the alkyl can be substituted by O-1-14C alkyl, the aryl can be substituted by fluorine, 1-8C alkyl, S-1-8C alkyl, O-1-14C alkyl, COO-1-8C alkyl, O-phenyl, N-(Ph)2 or 8-20C aralkenyl, and the heteroaryl can be substituted by 1-8C alkyl, O-1-8C alkyl, or 8-20C aralkenyl;    R19, R20, R21=H;    R25=1-14C alkyl or 7-10C aralkyl where the alkyl can be substituted by pyridiniumasteriskX and the pyridinium is substituted by 1-8C alkyl;    R28=1-3C alkylene optionally substituted by COOH, preferably 1C alkylene;    X=Cl, Br, I, or 6C aryl-S(O)2O where aryl is substituted by one 1-14C alkyl;    R30-R33=H;and    n=1.    Provided that R29 comprises group G; compound of formula (I) is dimeric