H 2 S dosimeter with controllable percolation threshold based on semi-conducting copper oxide thin films
H 2 S dosimeter with controllable percolation threshold based on semi-conducting copper oxide thin films
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DOI：
10.5194/jsss-6-163-2017
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发表时间：
2017-05
影响因子：
1
通讯作者：
C. Seitz;Giuliana Beck;J. Hennemann;C. Kandzia;K. Hering;A. Polity;P. Klar;Andrej Paul;T. Wagner;S. Russ;B. Smarsly
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文献类型：
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作者：
C. Seitz;Giuliana Beck;J. Hennemann;C. Kandzia;K. Hering;A. Polity;P. Klar;Andrej Paul;T. Wagner;S. Russ;B. Smarsly
抽象。铜氧化物，如CuO和Cu2O，是用于H2S检测的有前途的材料，因为与H2S可逆反应生成硫化铜（CuS，Cu2S）。沿着相变，电导增加了几个数量级。在CuOx膜上，H2S反应导致形成统计分布的CuxS岛。连续暴露于H2S导致岛生长，并最终形成贯穿整个系统的高导电路径：所谓的渗滤路径。相关的CuOx scinCuxS转化率称为渗滤阈值。这种明显的阈值导致膜电导的气体浓度依赖性开关状行为。然而，利用这种效果的CuO为基础的H2S传感器的制备，影响CuS路径演变的操作和形态参数的深刻理解是必要的。因此，这篇文章的重点是H2S检测的氧化铜薄膜的基本特征和结构参数的渗流阈值和开关行为的影响。特别是，两个重要的因素，即化学计量的氧化铜（CuO，Cu2O和Cu4O3）和表面形态，进行了详细的研究。通过射频磁控溅射工艺合成了CuOx薄膜，该工艺允许修改这些参数。可以表明，例如，对开关行为的影响主要由氧化铜的形态而不是化学计量决定。
Abstract. Copper oxides, such as CuO and Cu2O, are promising materials for H2S detection because of the reversible reaction with H2S to copper sulfides (CuS, Cu2S). Along with the phase change, the electrical conductance increases by several orders of magnitude. On CuOx films the H2S reaction causes the formation of statistically distributed CuxS islands. Continuous exposition to H2S leads to island growth and eventually to the formation of an electrical highly conductive path traversing the entire system: the so-called percolation path. The associated CuOx ∕ CuxS conversion ratio is referred to as the percolation threshold. This pronounced threshold causes a gas concentration dependent switch-like behaviour of the film conductance. However, to utilize this effect for the preparation of CuO-based H2S sensors, a profound understanding of the operational and morphological parameters influencing the CuS path evolution is needed. Thus, this article is focused on basic features of H2S detection by copper oxide films and the influence of structural parameters on the percolation threshold and switching behaviour. In particular, two important factors, namely the stoichiometry of copper oxides (CuO, Cu2O and Cu4O3) and surface morphology, are investigated in detail. CuOx thin films were synthesized by a radio frequency magnetron sputtering process which allows modification of these parameters. It could be shown that, for instance, the impact on the switching behaviour is dominated by morphology rather than stoichiometry of copper oxide.