Enhanced morphology and photoelectric properties of one-dimensional TiO2 nanorod array films.

• 1D TNA films with ideal morphology were prepared by the two-step process. • The optical performance of 1D TNA films was enhanced by narrowing the bandgap. • The 1D TNA films achieved efficient charge separation with higher photocurrent density. One-dimensional TiO 2 nanorod array films (1D TNA films) were prepared by the two-step process. The results show that the density of 1D TNA films is significantly improved with the presence of TiO 2 compact layer (TCL) and the hydrothermal reaction time of 15 h. The TiO 2 crystallinity is improved. The utilization efficiency of the visible light is increased with the lower concentration of crystal defects. The charge recombination center caused by the defects decreased, while the electrons and holes were effectively separated, thus the charge recombination rate was lowered, and better charge transport performance caused the transient photocurrent to increase significantly. [ABSTRACT FROM AUTHOR]