Semiconductor gas sensors based on hetero-cluster particles for VOC detection in ppb level

已经开发或提出了各种类型的气体传感器，并且它们中的一些已经被认为是用于各种目的的监测、处理或控制气体的关键装置。通过受体功能、转换器功能和利用因子对VOCs高灵敏度半导体气敏元件的影响，指出了在纳米和介观水平上进行结构控制对VOCs高灵敏度半导体气敏元件的重要性。在受体功能方面，采用反胶束法和表面修饰法对SnO_2胶体粒子进行了负载Pd等金属离子的表面修饰。结果表明，SnO_2纳米颗粒上PdO的粒径大小对气敏性能有很大影响。与传统浸渍法制备的负载PdO的SnO_2传感器相比，该传感器可以实现少量的PdO负载。对于换能器功能，还挑战了用其他氧化物掺杂每个颗粒以进行价态控制。我们调查了 关于我们 Fe^3^+掺杂对SnO_2晶体尺寸、电阻和传感器响应的影响。发现Fe^3+掺杂降低了载流子浓度和晶体尺寸。用所提出的理论很好地解释了电阻随氧分压的变化关系和传感器对H_2的响应。对于实用因素，通过增加晶粒尺寸来增加孔径，并通过形成晶粒的小簇（次级颗粒）来引入大孔，目标气体在其扩散到传感器装置中的途中与氧化物表面反应。所制备的SnO_2团簇溶胶可用于制备具有大孔结构的薄膜型气敏元件。从传感性能，它被发现，这样的簇溶胶作为前体溶液，以制备高性能的高阶结构控制的器件具有很高的潜力。为了研制出高灵敏度的气体传感器，必须将这三个关键因素融合在一个传感器器件中。少

Various kinds of gas sensors have been developed or proposed and some of them have been recognized as key devices to monitor, handle or control of gases for various purposes. In this study, importance of structure control in nano- and meso-level for high-sensitive semiconductor gas sensor to VOCs, which are large size molecules, was indicated through brief effects by receptor function, transducer function and utility factor. For receptor function, it was challenged to load each colloidal particle of SnO_2 with foreign metal like Pd by a reverse micelle method and a surface modification method for surface modification. It was found that the particle size of PdO on SnO_2 nano-particle influences the gas sensing property closely. Small amount of PdO loading can be achieved as compared with PdO-loaded SnO_2 sensor prepared by the conventional impregnation method. For transducer function, doping each particle with other oxides for valence control was also challenged. We investigated the eff … More ects of Fe^3^+ doping in SnO_2 on the crystalline size, electric resistance, and sensor response. The Fe^3+ doping was found to decrease the carrier concentration and crystalline size. The dependence of electrical resistance on oxygen partial pressure and the sensor response to H_2are well explained in terms of the proposed theory. For utility factor, by increasing pore size through an increase in grain size and introducing macropores through forming small clusters (secondary particles) of grains, the target gas reacts with the oxide surface on its way of diffusion into the sensor device. The prepared SnO_2cluster sols were useful for fabrication of thin film type gas sensor including the microstructure with larger pores. From the sensing properties, it was found that such cluster sols have high potentiality as a precursor solution to prepare high order structure controlled devices for high performance. In order to develop high-sensitive gas sensors, it was expressed that the three key factors should be fused together in one sensor device. Less