Plasmonic enhancement of the performance of dye-sensitized solar cell by core–shell AuNRs@SiO2 in composite photoanode

Abstract

A series of dye-sensitized solar cells (DSSCs) with differing amounts of Au nanorods (AuNRs) (coated with a SiO2 layer as a core–shell AuNR@SiO2 (AuNRS)) composited photoanodes are prepared. The influences of different amounts of AuNRSs on the performance of the composite photoanodes and DSSCs are investigated. Studies revealed that, by increasing the amount of AuNRSs, the intensity of the light absorption spectra of the photoanodes is gradually increased while the dye absorbed is reduced. The short-circuit current density (Jsc), open-circuit voltage (Voc) and photoelectric conversion efficiency (η) increased gradually first and then decreased with the increase of AuNRSs, while the charge transfer resistance R2 and the dark current showed an opposite change trend. The optimal properties were obtained in the 2.0 wt% AuNRSs doped DSSC, with a maximum Jsc of 15.88 mA cm−2, a highest Voc of 730 mV and a best η of 7.21%, giving 20.8%, 38 mV and 23.0% higher than those of the conventional pure TiO2-based DSSC, respectively. The significant improvements in the properties of the optimal DSSC are attributed to the increase of the light coupling and thus the light absorption of the dye due to the localized surface plasmon resonance of the AuNRSs.