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 three-electrode 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.