Highly ordered, bamboo type TiO2 nanotube (NT) arrays were prepared by anodization of Ti foils in an electrolyte of 0.5 wt% NH4F in ethylene glycol using square-wave voltage. The morphology of obtained arrays consisting of closely packed TiO2 NTs with inner diameter of 90 nm, wall thickness of 20 nm and length of 26 pm was characterized by scanning electron microscopy (SEM). Poly-crystalline anatase structure with crystallites of 28 nm in average size was determined by X-ray diffraction (XRD). Intensity-modulated photocurrent spectroscopy (IMPS) was employed to study the electron transport properties of TiO2 NT arrays used in dye-sensitized solar cells (DSSCs). Dye molecules were found to cover both the inner and outer surface of the bamboo type TiO2 NT arrays. Electrochemical impedance spectroscopy (EIS) showed reduced interfacial resistance and increased interfacial capacitance for the bamboo type TiO2 NT arrays compared with the smooth type arrays, indicating an increase in surface area of the bamboo type TiO2 NT arrays, which resulted in the higher dye loading. An increased conversion efficiency of 7.36% was achieved for the DSSCs based on the bamboo type TiO2 NT arrays attributing to the significant increase of dye loading resulted from the bamboo structure. (C) 2013 Published by Elsevier Ltd.