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(η)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,η=1.51%)and ZnO nanorod array DSSCs(J_(sc)=4.2 mA/cm^2,η=0.61%).
