Synergic effect of graphene and core−shells structured Au NR@SiO2@TiO2 in dye-sensitized solar cells

Abstract

Graphene and Au nanorods (AuNRs) coated with SiO2@TiO2 double shells (AuNR@SiO2@TiO2) were incorporated to form novel composite photoanodes in dye sensitized solar cells (DSSCs). The performances of the photoanodes and DSSCs are studied systematically. The short circuit current density (Jsc) and power conversion efficiency (PCE) of these composited DSSCs were greatly enhanced and the influences of the graphene, AuNRs and the SiO2@TiO2 double shells were revealed. The optimal properties with the maximal Jsc of 16.26 mA cm−2 and PCE of 8.08% are obtained in the DSSC co-doped with graphene and AuNR@SiO2@TiO2, significantly higher than those of the conventional DSSC with pure TiO2 photoanode by 37.7% and 32.9%, respectively. These significant enhancements in Jsc and PCE are attributed to the synergistic effect of graphene, the local surface plasma resonance of AuNRs, as well as the outer SiO2@TiO2 double shells, which result in the increased specific surface area and dye adsorption, the increased light absorption, the decreased charge transfer resistance R2 and electron recombination and thus the increased Jsc and PCE of the DSSCs.