Self assembled ZnO hollow spheres and hexagonal stacking disks by metal-organic chemical-vapour deposition

Abstract

Self-assembled ZnO hollow spheres and hexagonal stacking disks were synthesised by metal-organic chemical-vapour deposition. The growth process was investigated as a function of time and the sphere and disk structures were obtained in a narrow window of a near-zero oxygen partial pressure. The largest hollow sphere has a diameter up to 20 μm with a shell thickness of around 200 nm formed by nanocrystals or nanodisks. The hexagonal stacking disks were found to be covered with a few nanometres thick of metallic Zn observed by high-resolution transmission electron microscopy. The accumulation and dissociation of diethylzine through beta hydride elimination process in the near-zero oxygen partial pressure was thought to be the reason for the formation of the hollow spheres and stacking disks. Copyright © 2007 Inderscience Enterprises Ltd.