ZnO nanocrystallite aggregates synthesized through interface precipitation for dye-sensitized solar cells

ont matter & 2012 0.1016/j.nanoen.2 thor. s: chldwang@mail .edu (G. Cao). Abstract A novel interface precipitation method has been developed to synthesize hierarchically structured ZnO nanocrystallite aggregates. Such synthesized ZnO nanocrystallite aggregates were demonstrated as a promising structure for high power conversion efficiency when used as photoelectrode in dye-sensitized solar cells (DSCs). In comparison with ZnO nanoparticles synthesized by conventional homogeneous precipitation method, such hierarchical structure has larger specific surface area, more efficient dye-loading and effective light scattering within the photoelectrode; all result in an increased photocurrent. Furthermore, electrochemical impedance spectroscopy study revealed that reduced charge recombination in ZnO nanocrystallite aggregates resulted in enhanced Voc. As a result, a power conversion efficiency of 5.07% with commercially available dye N719 has been obtained without applying anti-reflection coating and chemical treatment, which was more than 200% of the power conversion efficiency achieved in ZnO nanoparticles synthesized by homogeneous precipitation method in aqueous solution. & 2012 Elsevier Ltd. All rights reserved.