title: Morphology and composition controlled growth of polar c-axis and nonpolar m-axis well-aligned ternary III-nitride nanotube arrays.
abstract: Control over the nanostructure morphology and growth orientation is in high demand for fundamental research and technological applications. Herein we report a general strategy to fabricate polar c-axis and nonpolar m-axis well-aligned III-nitride ternary nanotube arrays with controllable morphologies and compositions. By depositing AlN on the InN nanorod array templates and thermally removing the InN templates, InAlN nanotubes can be obtained. Polar c-axis and nonpolar m-axis nanotubes were formed on the c- and r-plane sapphire substrates, respectively. The nanotubes are single crystalline and highly ordered on the substrates, as revealed by X-ray diffraction, electron microscopy, and selected area electron microscopy characterization. It was found that the In droplets on top of the InN nanorods play a critical role in controlling the morphology of the nanotubes. By keeping or removing the In droplets, the obtained nanotubes exhibited both ends open or only one end open. And by varying the AlN deposition temperature, the In composition in the nanotubes can be changed from 0 to 0.29. The nanotube synthesis method is simple and can be applied to the formation of other III-nitride ternary (InGaN, and AlGaN) or quaternary (InAlGaN) alloy nanotube arrays.
authors.affiliation: Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083, People's Republic of China. hjli2009@semi.ac.cn sh-yyang@semi.ac.cn.
authors.forename: Huijie
authors.initials: H
authors.lastname: Li
authors.forename: Guijuan
authors.initials: G
authors.lastname: Zhao
authors.forename: Susu
authors.initials: S
authors.lastname: Kong
authors.forename: Dongyue
authors.initials: D
authors.lastname: Han
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Wei
authors.forename: Lianshan
authors.initials: L
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Chen
authors.forename: Shaoyan
authors.initials: S
authors.lastname: Yang