Detection mechanism in highly sensitive ZnO nanowires network gas sensors
Detection mechanism in highly sensitive ZnO nanowires network gas sensors
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DOI：
10.1016/j.snb.2019.05.079
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发表时间：
2019-10-15
影响因子：
8.4
通讯作者：
Lenoble, Damien
中科院分区：
文献类型：
--
作者：
Caicedo, Nohora;Leturcq, Renaud;Lenoble, Damien
金属氧化物纳米线在气体传感领域表现出极大的兴趣，因为它们即使在低温下也具有很大的响应，能够实现低功耗的气体传感器。然而，它们的响应仍然没有被完全理解，并且主要限于线性响应状态，这限制了针对特定应用的适当传感器的设计。在这里，我们分析了基于ZnO纳米线网络的传感器的非线性响应，既作为设备几何形状的函数，又作为对氧气暴露的响应。使用适当的模型，我们解开的纳米线电阻和网络中的纳米线之间的结的贡献。所应用的模型显示出非常好的一致性与实验数据，使我们能够证明，在室温下对氧的响应是由在低偏置电压下的势垒电位，并在较高的偏置电压的纳米线电阻开始发挥作用。该分析使我们能够找到适当的器件几何形状和工作点，以优化灵敏度。这种分析对于提供设计规则是重要的，不仅对于传感装置，而且对于使用具有不同材料和几何形状的纳米结构网络的电子学和光电子学中的应用。
Metal-oxide nanowires are showing a great interest in the domain of gas sensing due to their large response even at a low temperature, enabling low-power gas sensors. However their response is still not fully understood, and mainly restricted to the linear response regime, which limits the design of appropriate sensors for specific applications. Here we analyse the non-linear response of a sensor based on ZnO nanowires network, both as a function of the device geometry and as a response to oxygen exposure. Using an appropriate model, we disentangle the contribution of the nanowire resistance and of the junctions between nanowires in the network. The applied model shows a very good consistency with the experimental data, allowing us to demonstrate that the response to oxygen at room temperature is dominated by the barrier potential at low bias voltage, and that the nanowire resistance starts to play a role at higher bias voltage. This analysis allows us to find the appropriate device geometry and working point in order to optimize the sensitivity. Such analysis is important for providing design rules, not only for sensing devices, but also for applications in electronics and opto-electronics using nanostructures networks with different materials and geometries.