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. (C) 2010 Elsevier B. V. All rights reserved.