Morphological control of ZnO nanostructures on silicon substrates

ZnO nanostructures are grown on Au-catalyzed Si substrates by vapour phase transport between 800 and 1150 ∘C. Nanostructures grown at 800 ∘C are mainly rod-like in structure with diameters of <200 nm. Increasing growth temperature yields combination growth modes with 2D structures (nanowalls/nanosheets) connecting 1D nanorods at intermediate temperatures and a 3D growth mode of foam-like appearance at the highest temperatures. The present work indicates that it may be possible to systematically control the morphology of ZnO nanostructures by varying the growth temperature.