Interface Dependent Plasmon Induced Enhancement in Dye-Sensitized Solar Cells Using Gold Nanoparticles

Abstract

We report a study on plasmon-induced photoelectrochemistry from gold nanoparticles incorporated in dye-sensitized solar cells, assembled in two different configurations: TiO2/Aunanop/Dye and TiO2/Dye/Aunanop. Although the presence of the plasmonic material resulted in enhanced photocurrent and energy conversion efficiency, a decrease of fill factor was observed. Electrical modeling of the solar cells was performed and revealed a simultaneous decrease of parallel resistance and increase of series resistance, related to the presence of gold nanoparticles. The enhancement in photocurrent was related to a combination of strong plasmon-induced electric fields and light scattering, which overcome the loss in electrical properties. In addition, the overall increase in efficiency was found dependent on the interface where the plasmonic material is placed. The highest efficiency obtained from TiO2/Aunanop/Dye was attributed to a larger density of photoexcited electrons allowed to be transferred towards conduction band of TiO2.