Fabrication of three-dimensional network of ZnO tetratpods and its response to ethanol

被引:51
作者
Delaunay, Jean-Jacques [1 ]
Kakoiyama, Naoki [1 ]
Yamada, Ichiro [1 ]
机构
[1] Univ Tokyo, Sch Engn, Dept Eng Synth, Bunkyo Ku, Tokyo 1138656, Japan
关键词
metal oxide semiconductor; ZnO; nanostructure; tetrapod; gas sensor;
D O I
10.1016/j.matchemphys.2007.02.099
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
A three-dimensional network of ZnO tetrapods was fabricated on a quartz substrate. The interconnected tetrapods, having legs with length of several mu m and diameter in the 0.1-1 mu m range, were synthesized via a simple thermal oxidation reaction. Zn powder was heated in a furnace at a temperature of 900 degrees C and was made to react with air and water vapor. The content of water vapor in air was found to control the adherence onto the substrate and the morphology of the deposited layers. The layers developed a grain structure or a porous structure made of interconnected tetrapods, depending on the content of water vapor in air. The network of tetrapods which was obtained for a small content of water vapor formed a highly porous layer with a high surface to volume ratio. The tetrapod network was tested as a gas sensing element by measuring changes in its electrical resistance upon exposure to ethanol. The responses to ethanol were investigated as a function of the layer temperature and the ethanol concentration. The optimum temperature of the tetrapod network layer was found to be 400 degrees C, at which ethanol concentration as low as 0.5 ppm was easily detected. The tetrapod network exhibited a 10-fold increase in sensitivity when compared with a ZnO polycrystalline thick film. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:141 / 145
页数:5
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