Regrowth of Template ZnO Nanowires for the Underlying Catalyst-Free Growth Mechanism

详细信息    查看全文

• 作者：Hongjun Xu ; Yumin Hou ; Jingyun Gao ; Huichao Zhu ; Rui Zhu ; Yanghui Sun ; Xinli Zhu ; Yazhou Wang ; Xiaowei Wang ; Dapeng Yu
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：June 1, 2011
• 年：2011
• 卷：11
• 期：6
• 页码：2135-2141
• 全文大小：991K
• 年卷期：v.11,no.6(June 1, 2011)
• ISSN：1528-7505

文摘

Using pre-existing ZnO nanowires as lattice-matched templates, we have systematically studied the catalyst-free regrowth of ZnO nanostructures in a chemical vapor deposition (CVD) system. Because the templates (or crystal seeds) provided nanoscale preferential nucleation sites for the subsequent growth, changing ZnO supersaturation and growth temperature led to distinct growth modes, from nonepitaxy to homoepitaxy and from axial to radial epitaxy. The perfect borderless homoepitaxial ZnO nanostructures demonstrate the inherent growth behaviors that were especially researched with the help of their position-dependent optical properties. Neither the self-catalyst vapor鈥搇iquid鈥搒olid (VLS) growth mechanism nor the defects-induced growth mechanism could explain most of these homoepitaxial growth modes. Instead, two-dimensional nucleation and step propagation model based on avapor鈥搒olid (VS) scenario was suggested and all these phenomena were well interpreted. In addition, our work presents a very convenient and well-controlled way of fabricating useful nanostructures in a CVD system.