Improvement of dye-sensitized solar cell performance through infiltration of TiO2 nanoparticles between mesoporous TiO2 particles

•Spherical mesoporous TiO2 materials were obtained by a simple sol–gel method.•Physical mixture of TiO2 nanoparticle and mesoporous TiO2 was utilized for solar cell electrode.•Mixed electrode system exhibited higher DSSC performance.

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-TiO2 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.

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