TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Composition: A photovoltaic cell comprises the photoelectric material as part of a photo-anode, and further comprises a counter electrode and a redox electrolyte or a hole transfer material.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The oxide semiconductor is metal oxide chosen from oxides of titanium, tin, zinc, tungsten, zirconium, gallium, indium, yttrium, niobium, tantalum and vanadium. The metal oxide is titanium oxide. The titanium oxide is in the form of anatase titanium oxide, rutile titanium oxide, amorphous titanium oxide, metatitanate, orthotitanate, titanium hydroxide, and/or titanium oxide hydrate. The photoelectric material is supported on a substrate. The oxide semiconductor is in the form of a thin film having a thickness of 1-200 microns. Preferred Properties: The nanoparticles of oxide semiconductor have average diameter of 1-500 nm. Preferred Process: The sintered substrate-supported thin film of oxide semiconductor is further immersed in a solution of metal alkoxide, chloride, nitride or sulfide of the same metal as the oxide semiconductor and dried or re-sintered. The photoelectric material is treated with an auxiliary agent chosen from t-butylpyridine, alkylpyridine derivatives, amino triazoles, quinolines and carboxylic acids. Preferred Definitions:    Ar1=optionally substituted phenyl or naphthyl group substituted with hydroxyl group and carboxyl group in adjacent positions, preferably optionally substituted phenyl group substituted with a hydroxyl group and a carboxyl group in adjacent positions, or optionally substituted with hydroxyl group, carboxyl group, nitro group, halo group, methyl group and sulfonyl group and electron donating group;    Ar2=optionally substituted phenyl, naphthyl or heteroaryl group, and optionally substituted with at least one substituent chosen from hydroxy, carboxy, sulfonyl, amino, halo, sulfonamide, nitro, methoxy and methyl, or substituted with a group of formula (II): -N=N-L-R or formula (III): L-N=N-Ar3;    R=H, 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-6C cycloalkyl, OH, 1-6C OC alkyl, acyl, CO2H, 1-6C CO2C, CONH2, CONH(1-6C alkyl), CON(1-6C alkyl)2, NH2, NH(1-6C alkyl), N(1-6C alkyl)2, SO3H, SO3 1-6C alkyl, SO2NH2, SO2NH(1-6C alkyl), SO2N(1-6C alkyl)2, SH, S (1-6C alkyl), nitro, cyano, aryl, heterocyclic and heteroaryl, preferably H;    Ar3=optionally substituted aryl or heteroaryl group, preferably group or naphthyl group optionally substituted with methyl, methoxy, SO3H, OH, carboxy, amino or carboxy methoxy;    L=divalent linker, preferably divalent phenyl group, naphthyl group or biphenyl group optionally substituted with one to three groups chosen from methyl, methoxy, SO3H, OH, carboxy, amino or carboxymethoxy, or -Ar4-Q-Ar-5;    Ar4,Ar5=phenyl, naphthyl or triazine optionally substituted with one to three groups chosen from methyl, methoxy, SO3H, OH, carboxy, amino or carboxymethoxy;and    Q=S, NH, -CH=CH- or NHC(O)NH.    SPECIFIC COMPOUNDS - Six specific sensitizing dyes, such as Mordant Orange 6 of formula (I), Direct Red 1 of formula (II), Mordant Black 5 of formula (III), Mordant Yellow 16 of formula (IV), Direct Brown 2 of formula (V) and Direct Blue 163 of formula (VI), are claimed.