TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Solvent: The solvent is a nitrile compound.Preferred Dye: The dye has an acidic group.The ruthenium complex and/or methine dye is used as the dye.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Salt: The quaternary salt is selected from tetralkylammonium salts, imidazolium salts and pyridinium salts.The quaternary salt is preferably of formula (I).Q = quaternary ammonium salt;LINK = divalent linking group;R1 = substituent;n1 = 0-4; andn2 = 0 or 1.The molecularity of the quaternary salt in the treatment solution is equivalent to or more than the total number of the acidic group of the dye in the photosensitive layer. Q = tetralkylammonium salt having at least one alkyl group containing 6 or more C atoms.    EXAMPLE - A titanium dioxide dispersion was prepared in the same manner a disclosed in C.J. Barbe et al, J. Am. Ceramic Soc., 80, 3157 except that the autoclave temperature was 230 degreesC. The weight ratio of titanium dioxide was 11 wt.% and the average diameter was 10 nm. Then a 20 wt.% of polyethylene glycol was added to 100 wt.% of titanium dioxide dispersion and mixed to prepare a coating dispersion containing titanium dioxide.    The above-prepared coating dispersion was applied onto an electrically conductive surface of a transparent conductive support (thickness of 130 microns) using a doctor blade, dried at 25 degreesC for 30 minutes to provide a titanium dioxide layer. Used as the transparent conductive support was a conductive glass having a surface resistance of 10 Ohms/cm2, which was composed of a glass substrate and an electrically conductive layer of fluorine-doped tin oxide. Amount of the titanium dioxide in the resultant titanium dioxide layer was 19 m2/g, and thickness of the titanium dioxide layer was 13 microns.    Thus-obtained titanium dioxide electrode was cooled, and soaked in a dye adsorption solution composed of a dye of formula (A) and a mixture solvent of ethanol/t-butanol/acetonitrile = 1/1/2 at an adsorbing temperature of 45 degreesC for an adsorbing period of 10 hours to adsorb the dye (A) on the titanium dioxide electrode. Concentration of the dye in the adsorption solution was 0.01 mol/l. The resultant electrode was washed with ethanol and acetonitrile respectively, soaked in a treatment solution composed of quaternary salt of formula (II) and acetonitrile at 40 degreesC for 2 hours, washed with ethanol and acetonitrile respectively and dried under nitrogen gas stream, to prepare a dye-adsorbed titanium dioxide electrode.    The photoelectric cell was prepared by placing the x cm dye-adsorbed titanium dioxide electrode on a platinum-deposited glass of the same size. Then an electrolyte composition composed on 1,3-dimethyl imidazolium iodide (0.65 mol/l), t-butylpyridine (0.1 mol/l) and acetonitrile was permeated into a crevice between the dye-adsorbed titanium dioxide electrode and the platinum-deposited glass through capillarity, to produce a photoelectric cell.