Structural and optical properties of ZnO nanotower bundles

ZnO nanotower bundles have been grown on the electrochemically deposited ZnO thin film by a simple hydrothermal process. The influence of surface/interface defects on the structural and optical properties is studied by x-ray diffraction, selected area electron diffraction, and photoluminescence techniques. The formation of ZnO nanotowers and defects may be attributed to kinetic confinement and thermodynamic processes. A wide visible emission band covering nearly the entire visible region is related with the surface/interface defects. By controlling the surface area-to-volume ratio and the width change of the single ZnO nanotower, the emission properties of ZnO nanotowers can be well modified.