In this study a cross-linkable ruthenium complex dye, Ru(2,2'-bipyridine-4,4'-bicarboxylic acid)(4,4'-bis((4-vinyl-benzyloxy)methyl)-2,2'-bipyridine)(NCS)2 denoted as RuS, was applied to the solid-state dye-sensitized solar cell, by which the photovoltaic performance was superior to the traditional N3 dye. However, the power conversion efficiency (PCE) was only 1.48%, resulting from poor pole filling of the hole conductor, 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (spiro-OMeTAD). To modify the interface between RuS and spiro-OMeTAD, additional 4,4'-bis((4-vinylbenzyloxy) methyl)-2,2'- bipyridine (BVP) ligand was employed to crosslink with RuS. The cross-linked dye (denoted as RuS-BVP) on TiO2 was more sustainable and the PCE rose to 2.12%. Besides, the outward bipyridine groups of RuS-BVP are capable of chelating cations. As lithium bis(trifluoromethane)sulfonimide was applied to modify the interface between RuS-BVP and spiro-OMeTAD, the PCE increased to 2.55% and the interfacial resistance for charge transfer under sunlight dramatically decreased. As divalent cation compounds such as magnesium, calcium and barium acetylacetonate were individually adsorbed onto the RuS-BVP, the cell with magnesium acetylacetonate has the highest PCE of 2.82%, highest open circuit voltage and lowest interfacial resistance. The results suggest that the cations with higher charge density have stronger Coulomb's force to couple between RuS-BVP and spiro-OMeTAD. (C) 2018 Elsevier B.V. All rights reserved.