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 (Jsc) of 11.7 mA/cm2 and an overall solar-to-electric energy conversion efficiency (η) of 3.17% were achieved for the ZnO composite aggregate DSSCs, which were much higher than those obtained for the monodisperse aggregate DSSCs (Jsc = 6.9 mA/cm2, η = 1.51%) and ZnO nanorod array DSSCs (Jsc = 4.2 mA/cm2, η = 0.61%).