This study examined the structural properties of ZnO nanorods grown on Ti-buffer layers with different surface roughnesses of 1.5 and 4.0 nm. Vertically aligned ZnO nanorods were synthesized on Al2O3 substrates with a Ti-buffer layer by metal-organic chemical vapor deposition. X-ray diffraction revealed the ZnO nanorods grown on a smooth surface to have higher quality and better alignment in the ab-plane than those grown on the rough surface. Field-emission transmission electron microscopy (FE-TEM) measurements revealed a disordered layer at the ZnO/Ti interface. FE-TEM demonstrated that the Ti-buffer layer contained a mixture of ordered and amorphous phases. Energy dispersive spectroscopy (EDS) analysis revealed the Ti-buffer layers to be entirely oxides. (C) 2010 Elsevier B.V. All rights reserved.