TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: A polycarboxylic acid and amine are reacted in a polar solvent. A titanium alkoxide and an oxidizing agent are added, and a precursor solution which contains titanium complex anion coordinated to polycarboxylic acid and amine positive ion is obtained. Carbon dioxide, titanium alkoxide and oxidizing agent are reacted in a polar solvent. Subsequently, an amine is added, and a precursor solution having titanium complex anion coordinated with carbonic acid and dioxide ion, and amine positive ion is obtained. Carbon dioxide, titanium alkoxide, amine and oxidizing agent are reacted in a polar solvent. A precursor solution having titanium complex anion coordinated with carbonic acid and dioxide ion, and amine positive ion is obtained. The precursor solution is applied on a substrate, dried and heat-processed in inert gas, and coordinate bond of non-metallic elements such as nitrogen and metallic elements such as titanium is converted into firmer ionic bond. Thus, a light-active titanium dioxide film is formed. Coordinate bond of titanium-nitrogen of titanium complex having amino polycarboxylic acid as ligand, is converted into ionic bond by heat processing the precursor solution, and an oxygen substituted partially nitrided titanium dioxide film is formed. The titanium dioxide film formed from the precursor solution in inert gas, and titanium complex are combined, and photoelectromotive force is generated by ultraviolet ray and visible light, to obtain a titanium dioxide film. The light adsorption capability of the laminated titanium dioxide film is improved by heating processing the substrate of laminated titanium dioxide film in air. Preferred Composition: The amine positive ion is given by formula: (R1)(R2)(R3)(R4)N+, R5C6H4(CH2)nN+(R6)(R7) and R8C5H4NH+.R1-R4,R6,R7=H or 1-10C alkyl, at least one of R1-R4 is alkyl;R5,R8=dimethyl amino group, diethyl amino group, H or 1-10C alkyl;andn=0 or 1. EXAMPLE - Ethanol (in g) (20) and oxalic acid dihydrate (8.4) were taken in a flask. Dibutyl amine (5.7) was dropped and stirred at room temperature. Then, titanium tetra isopropoxide (6.3) was dropped and heat-refluxed for 3 hours. The obtained colorless transparent solution was applied on a quartz glass and preheated and at 70degreesC for 10 minutes and heat-processed at 500degreesC for 30 minutes. A titanium dioxide film having thickness of 106 nm was produced.