Effect of Seed Layer on Structural Properties of ZnO Nanorod Arrays Grown by Vapor-Phase Transport

By using different types of ZnO thin films as seed layers, we systematically investigated the effects of seed layers on the morphologies and growth behaviors of ZnO nanorods by the vapor-phase transport method. It was found that ZnO nanorods can be grown on a variety of polycrystalline ZnO seed layers. The formation of a network wetting layer facilitates the uniform growth of an aligned ZnO nanorod. However, once a continuous ZnO network layer is formed, the alignment will be independent of seed layer thickness and surface roughness. Our results indicate that a ZnO seed layer with a high c-axis orientation, good crystallinity, and less lattice stress leads to the growth of well-aligned ZnO nanorod arrays with uniform diameters and narrow density distributions.