A newly and interestingly small organic molecule, (R)-2,2'-dimethoxyl-3,3'-di(phenyl-4-yl-diphenyl-amine)-[1,1']-binaphthy l, was introduced into solid-state electrolyte to assemble dye-sensitized photoelectrical cell. With optimized molecular structure and composite porous TiO2 electrode, the solid-state device without any additives in electrolyte converted light to electric efficiency with a 0.07%. Under the assistance of some functional small-molecules in the electrolyte, solid-state devices showed an attractive conversion efficiency of 0.55%. In addition, the positive effects of functional additives on the photoelectrical performance, such as inhibiting interface charge recombination, improving hole-transporting properties and penetration of solid-state electrolyte, were discussed experimentally and theoretically in detail. (C) 2007 Elsevier B.V. All rights reserved.