Hydrothermal Synthesis of ZnO Nanorod Arrays and Their Morphology Control

By using the hydrothermal method, the ZnO nanorod arrays with different morphologies were synthesized on ZnO nanoparticle-coated transparent conductivity glasses (TCO) at low temperatures by controlling the pH value of precursory solutions. The ZnO nanorod arrays were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM) and ultraviolet-visible spectropho-tometer (UV-Vis). Furthermore, the mechanism was primary discussed. The results show that the ZnO nanorod is a single crystal and it grows along c axis. When the pH value is about 10.5, the array is well-aligned and the diameter of the nanorod is uniform. Optical characterization shows that the optical transmittance of the film is higher than 80% in the visible wavelength and its band gap is about 3.25eV.