Enhancement of properties of dye-sensitized solar cells by surface plasmon resonance of Ag nanowire core–shell structure in TiO2 films

Abstract

A series of TiO₂ nanocomposite photoanodes with different amounts of Ag nanowire (AgNW) coated with SiO₂ in a AgNW@SiO₂ core–shell structure are prepared by a ball milling method and applied to assemble a series of dye-sensitized solar cells (DSSCs). The influence of AgNW@SiO₂ on the performance of the TiO₂–AgNW photoanodes and DSSCs is investigated. Studies indicates that the range and strength of light absorption of the TiO₂ photoanodes, the photon capture ability of the dye molecules, and the short-circuit current density (J_sc) are significantly increased while the dark current is decreased due to the incorporation of AgNW@SiO₂. The optimal properties are obtained in a DSSC with a J_sc of 11.83 mA cm⁻², and an overall photoelectric conversion efficiency (η) of 6.26%, significantly superior to those of the DSSC with a pure TiO₂ photoanode. The enhancements of J_sc and η are attributed to the increase of light coupling and thus the light absorption of the dye due to the localized surface plasmon resonance and the possible enhanced light scattering of AgNW@SiO₂ in the photoanode.