XPS investigation of vacuum annealed vertically aligned ultralong ZnO nanowires
XPS investigation of vacuum annealed vertically aligned ultralong ZnO nanowires
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DOI：
10.1016/j.susc.2011.09.007
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发表时间：
2012-01-01
期刊：
影响因子：
1.9
通讯作者：
Wilks, S. P.
中科院分区：
文献类型：
--
作者：
Maffeis, T. G. G.;Penny, M. W.;Wilks, S. P.
利用x射线光电子能谱研究了以金层为催化剂在氮化镓上化学气相沉积制备的垂直排列ZnO纳米线的表面性质与超高真空退火温度的关系。纳米线长8.5微米，宽60纳米。500℃特高压退火后，表面碳含量脱除87%。对金强度的分析表明，在600℃退火后，金扩散到纳米线中，300℃退火去除了表面的水污染，并引起了02 eV的向上带弯曲，表明吸附的水分子充当了表面电子供体。超高压作用10天后，污染物重新被吸附，由除水引起的表面带弯曲被逆转。特高压实验也影响了纳米线的排列，使它们聚集在一起。这些结果对ZnO NWs的气敏应用具有明确的意义。(C) 2011 Elsevier B.V.版权所有
The surface properties of vertically aligned ZnO nanowires grown by chemical vapour deposition on GaN using a gold layer as a catalyst are investigated by X-ray Photoelectron Spectroscopy as a function of annealing temperature in ultra high vacuum (UHV). The nanowires are 8.5 mu M long and 60 nm wide. 87% of the surface carbon content was removed after annealing at 500 degrees C in UHV. Analysis of the gold intensity suggests diffusion into the nanowires after annealing at 600 degrees C. Annealing at 300 degrees C removes surface water contamination and induces a 02 eV upward band bending, indicating that adsorbed water molecules act as surface electron donors. The contaminants re-adsorbed after 10 days in UHV and the surface band bending caused by the water removal was reversed. The UHV experiment also affected the nanowires arrangement causing them to bunch together. These results have clear implications for gas sensing applications with ZnO NWs. (C) 2011 Elsevier B.V. All rights reserved.