TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The electrolyte is produced by heat-treating the complex salt of the imidazole and 1-20C diiodoalkane and iodine. Preferred Components: The imidazole is of formula (1 or 3). The complex salt of the imidazole and 1-20C diiodoalkane is a compound of formula (4). The electrolyte further comprises additive chosen from a nitrogen-containing additive and a lithium-containing additive, and non-volatile or low-volatile organic solvent. Cation and iodide ions are produced from a hydrolyzed, dehydrated and condensed product of complex salt of a silane substituted imidazole and 1-20C diiodoalkane and iodine.R1-R4=H, optionally substituted (1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 2-20C heteroaryl, 2-20C heteroaryloxy and 4-10C carbocyclic group), hydroxyl, cyano, or halogen atom;X=H, optionally substituted 1-20C alkyl, 6-20C aryl, or silicon-containing group of formula: -C(=O)-NH-(CH2)a-Si(-Y1)(-Y3)-Y2 (2);Y1-Y3=halogen, hydroxyl, 1-10C alkyl, 1-10C alkoxy or hydrogen, preferably ethoxy;a=1-10, preferably 3;andb=1-20, preferably 6.Preferred Composition: The content of the complex salt of the imidazole and 1-20C diiodoalkane is 10-50 weight parts with respect to 100 weight parts of electrolyte. The content of the iodine ion is 10-30 weight parts with respect to 100 weight parts of electrolyte. Preferred Cell: A solar cell comprises a porous film provided between electrode (I) and electrode (II), dye and electrolyte. SPECIFIC COMPOUNDS - 83 Specific imidazole compounds are claimed. E.g. 2-ethylimidazole of formula (A), 1-acetylimidazole, 2-ethyl-4-methylimidazole, N-(3-(triethoxysilyl)propyl)-2H-benz(d)imidazole-1(4H)-carboxamide, N-(3-(triethoxysilyl)propyl)-5-methyl-2H-benz(d)imidazole-1(4H)-carboxamide and N-(3-(trimethoxysilyl)propyl)-1,2-dimethyl-1H-imidazole-5-amine, and 3 specific 1-20C diiodoalkane are claimed such as diiodohexane, diiodoheptane and diiodononane.    EXAMPLE - 3-(Trimethoxy silyl)propyl isocyanate and benzimidazole were mixed in molar ratio of 1:1 and dissolved in anhydrous tetrahydrofuran, and the mixture was refluxed at 140 degrees C under argon atmosphere for 8 hours. Then solvent was removed from the mixture to obtain (N-(3-(triethoxy-4-silyl)propyl)-1H-benzimidazole-1-carboxamide). Then, obtained (N-(3-(triethoxy-4-silyl)propyl)-1H-benzimidazole-1-carboxamide) and 1,6-diiodohexane were mixed the molar ratio of 1:1. Then, 0.1 M lithium iodide, 0.05 M iodine and 0.5 M 4-tert-butylpyridine were dissolved in 3-methoxy propionitrile, and mixed with resulting mixture to obtain electrolyte. The obtained electrolyte provided solar cell having high photoelectric conversion efficiency, stability and durability.