二氧化锡复合材料及薄膜异质结气敏特性研究
发布时间：2018-11-16 11:41
【摘要】：气敏传感器作为检测气体的基础器件,在工业生产和日常生活中均有着广泛的应用。在气敏传感器中,二氧化锡气敏传感器具有灵敏度高、响应恢复特性好、成本低等优点,是目前应用最广泛的一种气敏传感器。但随着科技的进一步发展,对气敏传感器性能的要求越来越高,气敏传感器的敏感材料与结构仍需要进一步的优化。本文首先介绍了一种通过掺杂氯化钯和石墨烯得到二氧化锡复合材料,获得了一种能在近室温下工作的乙醇气体传感器。二氧化锡粉末通过化学沉淀法得到,其表面疏松多孔的、由直径约10-20 nm的纳米颗粒组成。通过在该粉末中掺入不同配比的氯化钯和石墨烯对比研究该复合材料对乙醇气体的响应特点。测试结果表明,掺入氯化钯和石墨烯不仅可以降低传感器的工作温度,而且对灵敏度及响应速度都有一定幅度的提升。特别是0.1 wt%rGO/3 wt%PdCl_2/SnO_2样品,该样品制备的传感器可在40°C环境下工作,灵敏度为4.6,响应时间为93 s,恢复时间为130 s,同时该传感器具有良好的稳定性与线性度。复合材料性能的提升主要是因为钯离子对氧负离子吸附的促进作用以及石墨烯对低温下载流子输运能力的提高作用。本文之后设计了一种采用MEMS工艺制备的二氧化锡薄膜气敏传感器。通过有限元分析软件分析了传感器微加热板模块的热效应,显示结构在80 mA加热电流下可以提供375℃的温度。之后采用相关工艺制备,其中二氧化锡薄膜通过磁控溅射法得到,经SEM与AFM测试表明,该工艺制备的二氧化锡薄膜微观上由纳米颗粒组成,薄膜表面致密、高低起伏较小。经过100ppm的乙醇气体气敏测试显示,100 nm厚的二氧化锡薄膜气敏传感器的灵敏度在250℃时最高,达到3.1,但其电阻不能在该温度下完全恢复。对比100nm、200nm、300nm厚的二氧化锡薄膜气敏传感器还发现,随着厚度的增加,传感器的灵敏度减小。本文随后提出采用异质结修饰的方法,分别采用氧化镍和氧化钨对100 nm Sn02薄膜气敏传感器进行修饰。研究发现,采用异质结结构能够解决薄膜式气敏传感器电阻恢复的问题,且能使得传感器灵敏度得到显著提高。特别是5 nm NiO/100 nm SnO_2气敏传感器,其在250℃时的灵敏度可达7.9,相比于纯二氧化锡薄膜提高了 155%,而且该传感器对100 ppb的乙醇气体仍具有一定响应,具有较好的低浓度响应特性。
[Abstract]:As the basic device for gas detection, gas sensors are widely used in industrial production and daily life. Among the gas sensors, tin dioxide gas sensor is the most widely used gas sensor because of its high sensitivity, good response and recovery characteristics, low cost and so on. However, with the further development of science and technology, the performance of gas sensors is becoming more and more demanding, and the sensitive materials and structures of gas sensors still need to be further optimized. In this paper, we first introduce a kind of tin dioxide composite material obtained by doping palladium chloride and graphene, and obtain an ethanol gas sensor which can work at near room temperature. Tin dioxide powder was obtained by chemical precipitation method. The surface of tin dioxide powder is porous and composed of nanoparticles about 10-20 nm in diameter. The response of the composite to ethanol gas was studied by adding different proportions of palladium chloride and graphene into the powder. The results show that the addition of palladium chloride and graphene can not only reduce the working temperature of the sensor, but also improve the sensitivity and response speed of the sensor to a certain extent. Especially for the 0.1 wt%rGO/3 wt%PdCl_2/SnO_2 sample, the sensor can work at 40 掳C, the sensitivity is 4.6, the response time is 93 s, and the recovery time is 130s. At the same time, the sensor has good stability and linearity. The improvement of the properties of the composites is mainly due to the promotion of palladium ions on the adsorption of oxygen negative ions and the enhancement of the carrier transport capacity of graphene at low temperature. In this paper, a tin dioxide thin film gas sensor prepared by MEMS process is designed. The finite element analysis software is used to analyze the thermal effect of the sensor micro-heating plate module. It is shown that the structure can provide a temperature of 375 鈩，
本文编号：2335415
[Abstract]:As the basic device for gas detection, gas sensors are widely used in industrial production and daily life. Among the gas sensors, tin dioxide gas sensor is the most widely used gas sensor because of its high sensitivity, good response and recovery characteristics, low cost and so on. However, with the further development of science and technology, the performance of gas sensors is becoming more and more demanding, and the sensitive materials and structures of gas sensors still need to be further optimized. In this paper, we first introduce a kind of tin dioxide composite material obtained by doping palladium chloride and graphene, and obtain an ethanol gas sensor which can work at near room temperature. Tin dioxide powder was obtained by chemical precipitation method. The surface of tin dioxide powder is porous and composed of nanoparticles about 10-20 nm in diameter. The response of the composite to ethanol gas was studied by adding different proportions of palladium chloride and graphene into the powder. The results show that the addition of palladium chloride and graphene can not only reduce the working temperature of the sensor, but also improve the sensitivity and response speed of the sensor to a certain extent. Especially for the 0.1 wt%rGO/3 wt%PdCl_2/SnO_2 sample, the sensor can work at 40 掳C, the sensitivity is 4.6, the response time is 93 s, and the recovery time is 130s. At the same time, the sensor has good stability and linearity. The improvement of the properties of the composites is mainly due to the promotion of palladium ions on the adsorption of oxygen negative ions and the enhancement of the carrier transport capacity of graphene at low temperature. In this paper, a tin dioxide thin film gas sensor prepared by MEMS process is designed. The finite element analysis software is used to analyze the thermal effect of the sensor micro-heating plate module. It is shown that the structure can provide a temperature of 375 鈩，
本文编号：2335415
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