Submicrometer-scale ZnO Composite Aggregate Arrays Photoanodes for Dye-sensitized Solar Cells

Submicrometer-scale ZnO composite aggregate arrays of nanorods and nanoparticles were prepared by simple wet-chemical route and studied as dye-sensitized solar cells (DSSCs) photoanodes. The ZnO composite aggregate arrays significantly improved the efficiency of DSSCs due to their relatively high surface area, fast electron transport, and enhanced light-scattering capability. A short current density (J(sc)) of 11.7 mA/cm(2) and an overall solar-to-electric energy conversion efficiency (eta) of 3.17% were achieved for the ZnO composite aggregate DSSCs, which were much higher than those obtained for the monodisperse aggregate DSSCs (J(sc) = 6.9 mA/cm(2), eta = 1.51%) and ZnO nanorod array DSSCs (J(sc) = 4.2 mA/cm(2), eta = 0.61%).