There are two factors on the efficiency of dye-sensitized solar cell (DSSC): one is the amount of dye adsorbed, and the other is contact resistance. In this study, TiO2 nanoparticles (nano-TiO2, about 20 nm particle size) were infiltrated between mesoporous TiO2 (meso-TiO2) particles with about 300 nm particle sizes, in order to reduce the contact resistance of TiO2 electrodes. The infiltrated nano-TiO2 can facilitate electron transfer between meso-Ti02 particles by filling the empty volume of DSSC electrodes. As a result, the TiO2 electrode containing 65 wt% of meso-TiO2 and 35 wt% of nano-TiO2 exhibited the highest performance of DSSC. (C) 2014 Elsevier Ltd. All rights reserved.