One dimensional ZnO nanostrucures grown on ZnO/Si by hydrothermal process

Abstract

Nanostructured semiconducting metal oxides such as nanotube, nanowires, nanoribbons and nanofibers are of considerable interest for solar energy conversion, sensors and in various electronic applications. In this study, ZnO nanofibers with extremely high length/diameter ratio and well-aligned ZnO nanorod arrays were synthesized by hydrothermal method, respectively, on Si substrates. Si substrates were covered with predeposited ZnO films as seed layers, which were deposited by DC magnetron sputtering. A growth mechanism involving nanorods were built from tiny nanowires of smaller diameter fusing together was inferred from SEM study of ZnO nanorod arrays. Also, growth positions of ZnO nanorod arrays were easily controlled via coating the ZnO seed layer with patterned photoresist “mask” fabricated by conventional photolithography. ZnO nanostructures would not grow on the organic mask due to the lack of ZnO nucleation sites on the organic resist layer. The design and preparing process of these ZnO nanostructures are in principle substrate-independent and occurs on flat surfaces regardless of their crystallinity or surface chemistry.