Effect of magnetic gamma-iron oxide nanoparticles on the efficiency of dye-sensitized solar cells

Abstract

In this study, we report on an internal magnetic field effect, originating from magnetic γ-Fe₂O₃ nanoparticles (NPs) dispersed into nanocrystalline TiO₂ film, which improves the performance of dye-sensitized solar cells (DSSCs). The DSSCs based on γ-Fe₂O₃/TiO₂ composite photoelectrode at an optimal amount of ∼1.5 wt% γ-Fe₂O₃ NPs exhibit an energy conversion efficiency of 6.92%, which is increased by 18% compared to that of DSSCs based on pure TiO₂ photoelectrode (5.84%). The role of the magnetic property of γ-Fe₂O₃ NPs on the PCE of DSSCs is investigated. It is found that the internal magnetic field, originating from the γ-Fe₂O₃ NPs in the TiO₂ electrodes, is the key factor leading to the improved photogenerated electron transfer ability and reduced charge recombination.