Dye-Sensitized Solar Cells Based on Hybrid Photoanodes Consisting of ZnO Nanorods Embedded in TiO2 Nanoparticles

One-dimensional (1D) nanostructures such as nanotubes, nanowires and nanorods (NRs) with suitable properties are emerging as novel candidates for integration into photoanodes (PAs) of dye-sensitized solar cells (DSSCs). In this work, a hybrid PA-based DSSC is designed, which consists of a mesoporous layer of TiO2 nanoparticles (NPs) modified with ZnO NRs. The presence of NPs imparts an increase of loading dye while the NRs facilitate charge transport and avert electron recombination in the system. We report a remarkable enhancement in power conversion efficiency of about 48.1% with respect to the hybrid PA-based DSSC, resulting in an efficiency of 4.91% mainly dictated by a high short-circuit current (J(sc)) of 13.46 mA/cm(2). Such excellent performance is attributed to the improved charge transport, better injection rate and lowered recombination of photoelectrons on the hybrid PA. The results strongly suggest that the ZnO NRs/TiO2 NP-based PAs accomplish a complementary effect in DSSC devices and consequently might be extended to similar applications.