ZnO nanostructures grown by low temperature methods

Abstract

In this work, two low-temperature processes, electrochemical deposition and atomic layer deposition, are chosen to synthesize ZnO films, nanorods and nanotubes. The important roles of the key parameters for ZnO ECD are discussed by using Au surfaces as cathodes. The properties of the ZnO nanostructures in relation to the Au interfaces with different crystal structures are studied for the first time. Tunable ZnO nanostructures can be obtained by adjusting ECD conditions or using different templates. The effects of in-situ ECD conditions optimization, post-thermal-annealing and surface-treatment are investigated. Synthesis of p-type ZnO is demonstrated under an applied electric field. By using ALD, epitaxial n-ZnO/ p-GaN heterojunction with blue emission are demonstrated. The synthesis of vertically aligned ZnO nanotube arrays on Si substrates are successfully carried out and characterized. Finally, GaN/ZnO core/shell nanostructures are demonstrated to improve the crystallographic quality of ZnO nanostructures grown by ALD.