Effect of Temperature, Time, Concentration, Annealing, and Substrates on ZnO Nanorod Arrays Growth by Hydrothermal Process on Hot Plate

Well aligned 1D ZnO nanostructures are important for optoelectronic and nanoscale electronic devices. In this report, 1D ZnO nanorods were synthesized by very simple, low cost, low temperature hydrothermal process. An effect of concentration, growth time, growth temperature, seed layer annealing, and seed layer thickness was investigated. The synthesized ZnO nanorods were characterized by scanning and transmission electron microscopies, X-ray diffraction, Raman and ultraviolet–visible spectroscopies. Growth parameters were found to influence strongly on the morphology, orientation, diameter, length, and density of the ZnO nanorod arrays. The growth temperature 80–90°C, seed layer annealing at 300–400°C, growth time 3 h, 0.025 M precursor concentration, and 0.2–0.3 M seed layer solution concentrations are more favorable conditions for better orientation and excellent crystallinity of the ZnO nanorods.