Effects of ZnO template thickness on the synthesis of 1-D ZnO nanostructures

1-D ZnO nanostructures were fabricated by the thermal evaporation method on ZnO templates which were thin films with a preferred orientation along the c-axis and were prepared by magnetron sputtering. These ZnO nanostructures were synthesized by direct reaction between metallic Zn powder and oxygen gas on ZnO templates of various thicknesses at a reaction temperature of 700°C. Although at a template thickness of <300 nm ZnO nanorods grew in a slightly inclined manner, vertical well-aligned ZnO nanorods were produced on ∼360-nm ZnO film. However, when template thicknesses were increased, the ZnO nanostructures produced adopted a network-like rather than a rod configuration. The origin of this configurational change is ascribed to variations in preferred orientation along the c-axis and in the grain size of ZnO templates, depending on the thickness of the ZnO templates.