Comparison of the gas sensing performance of SnO2 thin film and SnO2 nanowire sensors
Comparison of the gas sensing performance of SnO2 thin film and SnO2 nanowire sensors
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DOI：
10.1016/j.snb.2012.02.025
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发表时间：
2012-04-01
影响因子：
8.4
通讯作者：
Grogger, W.
中科院分区：
文献类型：
--
作者：
Brunet, E.;Maier, T.;Grogger, W.
为了优化气体传感器器件的性能，纳米晶SnO 2薄膜和单晶SnO 2纳米线传感器已被表征为目标气体CO，CH 4，H-2，CO2，SO2和H2S。在最佳工作温度下-从250摄氏度到400摄氏度变化-SnO 2薄膜传感器检测CO，CH 4，CO2和SO2的响应范围为23- 34%，H-2和H2S的响应范围超过80%。SnO 2纳米线传感器对CO、H2-和SO2的响应范围为1-8%，对H2S的响应范围为29%，而CH 4和CO2未被检测到。考虑到薄膜传感器的暴露表面积是单个纳米线的800倍，我们将撞击传感器表面的CO气体分子的数量与电子的数量相关联，在薄膜传感器的情况下，单个检测到的电子需要类似于2760个气体分子撞击传感器的表面。对于纳米线传感器来说，单个电子的检测只需要大约86个气体分子，因此SnO 2纳米线传感器的检测效率比SnO 2薄膜传感器高30倍以上，这归因于没有晶界。从我们的测量，我们得出结论，单晶SnO 2纳米线传感器提供了更高的灵敏度和改进的交叉灵敏度比他们的纳米晶体对应。(C)2012爱思唯尔有限公司版权所有。
In order to optimize the performance of gas sensor devices, nanocrystalline SnO2 thin film and single crystalline SnO2 nanowire sensors have been characterized for the target gases CO, CH4, H-2, CO2, SO2 and H2S. At optimum operating temperature - varying from 250 degrees C to 400 degrees C - the SnO2 thin film sensor detects CO, CH4, CO2 and SO2 with responses in the range of 23-34%, H-2 and H2S with responses above 80%. The SnO2 nanowire sensor shows responses in the range of 1-8% for CO, H-2 and SO2, 29% for H2S, while CH4 and CO2 are not detected. Taking into account that the exposed surface area of the thin film sensor is 800 times larger than that of the single nanowire, we have correlated the number of CO gas molecules impinging the sensors' surface with the number of electrons, which are actually detected as sensors' response for the target gas CO. In case of the thin film sensor a single detected electron requires similar to 2760 gas molecules impinging the sensor's surface. For the nanowire sensor only similar to 86 gas molecules are required for a single detected electron. The SnO2 nanowire sensor thus has a detection efficiency more than 30 times higher than the SnO2 thin film sensor, which we attribute to a lack of grain boundaries. From our measurements we conclude that single crystalline SnO2 nanowire sensors provide a higher sensitivity and an improved cross-sensitivity than their nanocrystalline counterpart. (C) 2012 Elsevier B.V. All rights reserved.