Plane-direction dependence of growth behavior of ZnO nanorods grown on sapphire substrate

ZnO nanorods were synthesized on ZnO seed layer covered sapphire substrates with different orientations by hydrothermal method. The surface morphologies of ZnO seed layer were analyzed by atomic force microscope. The shapes of ZnO nanorods were characterized by scanning electron microscopy. The c-axis oriented ZnO nanorods along surface normal were synthesized on A-plane and C-plane sapphire substrates. While, ZnO nanorods grown on R-plane sapphire were slant to the substrate and crossed each other.