High-density well-aligned arrays of monocrystal ZnO nanorods with small diameters have been successfully synthesized using zinc powder evaporation method on amorphous ZnO buffer layers prepared by simply thermal oxidation of ion beam sputtered Zn films.The morphologies of buffer layers and the nanostructures grown on these ZnO films with different thicknesses have been characterized and analyzed.The results show that as the thicknesses of Zn films increase

the morphologies of ZnO films are changing from isolated particles to continuous films

and the growth of ZnO nanorods from around those particles irregularly to along \ direction perpendicular to the substrates

with pronounced improvement of alignment

compactness and uniform distribution.The effect of the configuration of ZnO buffer layer on the growth of ZnO nanorods has also been discussed.