Synthesis And Characteristics Of Ordered One-dimensional Nanostructured Semiconductor Materials

In recent years, there has been increasing interest in the fabrication of one-dimensional nanostructures because of their potential utilization in electronic, magnetic, optical, and micromechanical devices. Highly ordered nanowire or nanotube arrays are particularly important for obtaining scaled-up functional devices for use as microelectrode, probes, and data storage devices. The ability to precisely prepare such structures on a large scale is an important goal of materials science. One strategy is to use porous nanochannel alumina (AAO) template to fabricate such structures. An important advantage of the template method is that the nanowires prepared in this way can be diameter-controllable and well defined. Anodic porous alumina with controllable pore size is very important for its uses as template. However, the range of the cell size of the anodic porous alumina obtained by naturally occurring self-ordering has been limited. So far, the conditions for preparing anodic porous alumina with controllable pore size have not been reported. In this paper, we report the fabrication of highly orderedhexagonal close-packed nanochannel alumina (AAO) template with controllable pore diameter by the anodic oxidation of high purity aluminum sheets, and the synthesis of ordered Carbon nanotube, ZnO nanowire arrays within the nanochannel alumina templates. The main results and conclusion can be summarized as following:(1) Alumina templates with highly ordered nanochannel arrays were synthesized by means of the electrochemical anodization.(2) Using ethyne as source gas, CNTs were successfully synthesized by CVD method. By comparing different synthesis technics, the influences of parameter to the grow of CNTs, such as catalysts, growth time, reaction temperature and ratio of all kinds of carrier gases were investigated. The results showed that the influence of carrier gas, reaction temperature, and the growth time on synthesis of CNTs was significant. In conclusion, a better condition for carbon nanotube growth was obtained. Through analyzing Raman Spectrum of samples, GM (graphite mode) and CNTs' characteristic peak-RBM (Radial Breathing Mode) was indicated. Field emission properties of CNTs were systematically studied and the result showed that the prepared CNTs had better field emission properties with low turn-on field and high emission current density.(3) Ordered semiconductor ZnO nanowire arrays embedded in anodic alumina the anodic aluminum oxide (AAO) templates were fabricated by electrodepositing ZnO in the nanochannels of AAO. XRD and SAED show that the ZnO nanowire is single crystal ((101) lattice plane).