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Abstract: Three kinds of ZnO nanowire arrays were fabricated on Au coated (110)silicon wafer by using of heating the mixture of zinc oxide (ZnO) and graphite powders at various depositing temperature. The synthesized samples were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analytic technology, respectively. Structural analyses revealed that the morphologies and crystal microstructures of ZnO nanoarrays were related with the substrate temperature. And control to the growth morphologies can be achieved by carefully tuning the depositing temperature. The testing results to different nanowire arrays showed that the properties of field emission follow the Fowler–Nordheim law. The quais-aligned ZnO nanowire array sample synthesized at 750°C had the lowest turn-on field of 7.4V/μm, highest β of 1028. This largest emission efficiency is attributed to the clear tip and appropriate coverage density. As well as the nanowires are straight with long length and parallel to each other with good crystal quality. The experimental results could be very useful for field emission materials and other nanoelectronics device applications. [Copyright &y& Elsevier]

Abstract: Two kinds of different aligned zinc oxide (ZnO) crystal microtube arrays were prepared on silicon (100) substrates by using of a simple thermal chemical reaction vapor transport deposition method. The synthesizing processes were done by using of heating the mixture of zinc oxide and graphite powders at 1150°C in a quartz tube with one side opened to the air. The O2 gas (99.9%) and air had been introduced as the assistant gases, respectively. Both the flow rates were 100ml/min. And the temperature of the Si (100) substrate region was about 400°C. There is no other metal catalyst on the Si wafers in the process. After growing for 30min, one kind of synthesized sample is trumpet-shaped hexagonal microtube arrays assisted with O2 gas and another produced sample is the uniform hexagonal microtubes only assisted with air. As the increasing of preparing time, their maximal lengths can range from several 10μm to mm scale. The microstructure, room temperature photoluminescence properties and growth mechanism of both aligned microtube arrays were investigated and discussed. [Copyright &y& Elsevier]