Three dimensional(3D) ordered macro/mesoporous titanium dioxide inverse opal (TiO2-IO) electrodes were fabricated via a sol-gel method with polyethylene glycol(PEG2000) treatment. The effects of PEG2000- treatment on the formation of TiO2-IO

the photovoltaic parameters and dye sensitized solar cells (DSSCs) efficiency were investigated. Macroporous templates with oval structures were prepared by using the self-assembly of monodispersed polystyrene (PS) microspheres. Titanium alkoxide precursors containing PEG2000 (as the mesopore directing agent) were infiltrated into the macroporous templates. 3D ordered macro/mesoporous TiO2-IO films were obtained after removing the PS and PEG2000 by calcinations. This kind of 3D macro/mesoporous electrode results in a better dye absorbtivity and enhanced DSSC efficiency. The experiments demonstrate that this enhanced efficiency not only results from active sites to adsorb dye

but also may lie in the decreased characteristic impedances of the DSSCs

which is attributed to the introduction of the mesopores in the TiO2-IO electrode. However

an excessive quantity of PEG2000 results in a drop of photoelectric conversion efficiency because of the damage of the macroporous structure with excessive PEG-treatment.