A Ru(2,2'-bipyridine-4,4'-dicarboxylic acid)(2)(NCS)(2) [RuL2(NCS)(2)]/di-(3-aminopropyl)-viologen (DAPV)/tin oxide (SnO2) system was prepared and applied to extensive photocurrent generation with its maximum surface area. The SnO2 thin films on tin-doped indium, oxide (ITO) were prepared using the chemical bath deposition method. Then, RuL2(NCS)(2)/DAPV on SnO2/ITO was easily prepared using self-assembled monolayers (SAMs). The photocurrent measurement of the system showed an excellent photocurrent of 20 nA cm(-2) under the air mass 1.5 conditions (100 mW cm(-2)), which was increased by a factor of four compared to ones without SnO2 layers. (C) 2008 Elsevier B.V. All rights reserved.