Conductivity of TiO2 nanotubes: Influence of annealing time and temperature

In the present study we investigate the electrical conductivity of self-organized TiO2 nanotube layers, grown by anodization of Ti in fluoride containing electrolytes. In particular, we explore the effect of annealing (time and temperature) on the solid-state conductivity of TiO2 nanotubes and show that under optimized annealing conditions the resistance of these self-organized arrays can be lowered by several orders of magnitude. The findings are very significant in view of an optimized use of TiO2 nanotubes in electrical and photoelectric applications.