Cosensitized Solar Cells Based on a Flower-Like ZnO Nanorod Structure

We shall present a cosensitized solar cell with sequentially assembled CdS quantum dots (QDs) and black dye on a flower-like ZnO rod nanostructure. As revealed by UV-vis absorption spectrum and scanning electron microscopy CdS QDs and black dye can be effectively adsorbed onto a flower-like ZnO nanorod array. Besides acting as a sensitizer, CdS QDs layer helps to prevent formation of Zn²⁺/dye complex. CdS QDs also provide intermediate energy levels for excited electron transfer from black dye to ZnO film. A power conversion efficiency as high as 3.26% was achieved for CdS QD and black dye cosensitized ZnO photoanode under the illumination of one Sun (AM1.5G, 100 mW/cm²).