The present work reports on the effect of thermal annealing on electrical, optical and structural properties of low aspect ratio self-organized TiO2 nanotube layers formed by anodization of Ti. The average inner diameter and length of the nanotubes was 100 nm and 1 mu m, respectively. From the whole range of temperatures (300-600 degrees C), annealing at 400 degrees C leads to the formation of crystalline TiO2 nanotube layers with anatase structure offering best electrical and photo-electrochemical properties. Conducting atomic force microscopy studies have been explored for the first time to identify the annealing temperature of nanotube TiO2 layers with best electrical properties. (C) 2016 Elsevier Ltd. All rights reserved.