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Zinc oxide （ZnO）, an important wide band gap semiconductor, possesses excellent opto-electric and piezoelectric properties, high gas sensing-characteristics and good biocompatibility, and has wide applications in light-emitting diodes, photodetectors, transparent conducting films, solar cells, gas sensors and so on. The crystal structure of ZnO makes it easy to prepare nanomaterials with various morphologies, which provides much room for developing devices based on ZnO nanostructures. Electrodeposition has the advantages of low synthesis temperature, simple process, wide compatibility to various substrates, and low cost, which facilitates a large-scale production. Here we focus on the electrodepositin of ZnO nanorod arrays and ZnO/mercurochrome hybrid films on the F-doped SnO2 conducting glass substrates, and the characterization of the photoluminescent properties of the ZnO nanorod arrays, and the applications of the ZnO/mercurochrome hybrid films in dye-sensitized solar cells.ZnO nanorod arrays were synthesized by the electrodeposition method using the three-electrode configuration at a constant potential, which Zn（NO3）2 aqueous solution was used as the liquid electrolyte. The microstructures and morphology, crystalline orientation, and length of the nanorods were characterized by a scanning electron microscope, an X-ray diffractometer, and a profilometer. The photoluminescent emission spectra of the ZnO nanorod arrays were measured using a fluorescence spectroscope. The effects of the substrate size, the type of counter electrode, the Zn2+initial concentration, and the deposition potential on the diameter, length and distribution density of the ZnO nanorod arrays were systematically investigated. It is shown that, the ZnO nanorod arrays only exhibit one emission peak centered at ca. 400 nm, suggesting that the ZnO nanorods have fewer defects and possess good crystal quality.ZnO/mercurochrome hybrid films were electrodeposited on the FTO glass substrates using the same three-electrode configuration, which mercurochrome was added into the Zn（NO3）2 aqueous solution. The optical absorption property of the hybrid films was characterized by an ultraviolet-visible spectrophotometer. The effects of initial concentration of mercurochrome, the deposition potential and the Zn2+initial concentration on the morphology and optical absorption of the ZnO/mercurochrome hybrid films were systematically investigated. It is shown that, the hybrid film deposited at the Zn2+initial concentration of 0.02 M, the potential of -1.0 V, the mercurochrome concentration of 60μM, respectively, exhibited the best optical absorption property. To apply the the ZnO/mercurochrome hybrid films into dye-sensitized solar cells, three kinds of photoanodes were fabricated: the mercurochrome-sensitized ZnO nanorod arrays by immersing into the mercurochrome solution to adsorb the dye, the as-prepared ZnO /mercurochrome hybrid film with best optical absorption and the same hybrid film followed by the desorption and re-adsorption of mercurochrome. The solar cells based on the three photoanodes were assembled with the same Pt counter electrode, respectively, and their photocurrent-voltage curves were measured. We find that, the solar cells based on the hybrid film followed by the desorption and re-adsorption exhibited the better conversion efficiency than the cell based on the ZnO nanorod arrays by immersing into the mercurochrome solution, indicating that the ZnO/mercurochrome hybrid films prepared by the electrochemical deposition can improve the performance of the solar cell based on the ZnO nanorods and mercurochrome.
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