Effects of characteristics on the photoelectric properties of TiO2 nanotube array

In this study, we investigated the photoelectric properties of TiO2 nanotube array films which were fabricated by electrochemical anodization on Ti metal substrates. The effects of annealing temperature and reaction conditions on the solid state conductivity of TiO2 nanotubes were explored. The samples were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The photoelectrochemical response of the TiO2 nanotube array is studied under UV illumination with transient photoresponse technique in a threeelectrode system. The results show that enlarging the nanotube diameter could decrease the transition time and the resistance of carrier, which results to the improvement of photo-generated current. Our research indicates that the less fluorinion residues on the nanotube array are, the higher transient photovoltage and photocurrent is. In addition, the TiO2 nanotube array mainly composing of anatase could improve the photoelectric conversion properties. The findings are very significant in view of an optimized use of TiO2 nanotubes in electrical and photo electric applications.