Photovoltaic properties of Ru(2,2'-bipyridine-4,4'-bicarboxylic acid)(4,4'-bis(11-dodecenyl)-2,2'-bipyridine)(NCS)(2) (denoted as Ru-C) related to its adsorption behavior onto the mesoporous titanium oxide (TiO2) were investigated in association with its amphiphilic structure compared with those of Ru(4,4'-dicarboxy-2,2'-bipyridine)(2)(NCS)(2) (commonly known as N-3 dye). Both dyes tended to aggregate and form vesicles in their acetonitrile/tert-butanol solutions. As the vesicles were adsorbed to TiO2, the dyes which did not participate in bonding to TiO2 would re-dissolve into the solution and create the voids on the surface of TiO2. The voids for N-3 dyes would be filled in time, whereas a great deal of voids for Ru-C dye remained, presumably due to its aliphatic side chains retarding further adsorption. The dye sensitized solar cell (DSSC) using Ru-C dye has lower power conversion efficiency compared with N-3 dye, which is partly due to the remaining voids that increase the charge recombination. Besides, the N-3 dye that is capable of injecting the excited electrons from both ligands to TiO2 also enhances the photocurrent. Therefore, although using amphiphilic dye for DSSC may have a merit of long term stability, its tendency of void formation on TiO2 mesoporous layer needs to be concerned. (C) 2012 Elsevier Inc. All rights reserved.