Microstructure and optical and electrical properties of TiO 2 nanotube thin films prepared by spin‐coating method

Titanium dioxide nanotubes prepared by hydrothermal method and the TiO 2 films and TiO 2 nanotube film were prepared by spin‐coating method. The TiO 2 nanotube film and a part of TiO 2 film were annealed at 150°C for 1 h, while the another part of TiO 2 film was annealed at 500°C. The high‐resolution transmission electron microscopy analysis indicated that the TiO 2 nanotubes prepared by hydrothermal method have been crystallised and the lattice plane indices corresponded to anatase {200}, and the TiO 2 nanotube grown along the 〈100〉 direction. The atomic force microscopy results show that the surface morphology of the TiO 2 film annealed at 150°C was smooth and uniform (0.62 nm in roughness) compared to the surface morphology of TiO 2 film annealed at 500°C (roughness is 2.41 nm). For the TiO 2 nanotube film, the nanotube fragments were uniformly dispersed in the base and the complete films have been prepared and the roughness was reached to 6.4 nm. The optical properties showed that the visible light transmittance of the TiO 2 nanotube film was larger (larger than 95%) than the TiO 2 film. The electrical properties showed that square resistance of TiO 2 nanotube film was smaller than that of TiO 2 film.