Photoluminescence studies from ZnO nanorod arrays synthesized by hydrothermal method with polyvinyl alcohol as surfactant

Well-aligned ZnO nanorod arrays have been synthesized by a simple hydrothermal method with polyvinyl alcohol as surfactant on F:SnO₂ conductive glasses substrates. Visible violet photoluminescence has been observed at room temperature. A series of annealing treatments in different environments have been made in order to investigate the nature of these emissions. The violet emission shows no change after annealing in air, while shifts to the ultra-violet region after annealing in H₂. It is concluded that the violet emission is due to V_Zn⁻ defect formed at the surface of the ZnO nanorods.