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，其中一些已经被认为是用于各种目的的气体监测、处理或控制的关键设备。在本研究中，通过受体功能、传感器功能和利用因子的简单影响，说明了高灵敏度半导体气敏传感器在纳米和介观水平对VOCs这一大分子的结构控制的重要性。在受体功能方面，采用反胶束法和表面改性法对SnO_2胶体颗粒进行表面修饰，并在每个胶体颗粒上负载类金属钯。结果表明，SnO_2纳米颗粒表面的PdO颗粒大小对气敏性能有很大的影响。与传统浸渍法制备的PdO负载型SnO2传感器相比，PdO负载量较小。对于换能器功能，在每个颗粒中掺杂其他氧化物以进行价态控制也是一个挑战。我们调查了Eff…Fe^3^掺杂对SnO_2的晶粒度、电阻和传感器响应的影响。Fe^3掺杂降低了载流子浓度和晶粒度。该理论很好地解释了电阻与氧分压的关系以及传感器对H_2的响应。对于效用因子，通过增加颗粒尺寸来增加孔径，并通过形成小颗粒簇(二次颗粒)来引入大孔，目标气体在其扩散到传感器器件的方式上与氧化物表面反应。所制备的SnO2团簇溶胶可用于制作具有较大气孔的薄膜气敏元件。从传感性能来看，这种团簇溶胶有很高的潜力作为制备高性能高阶结构可控器件的前驱溶液。为了开发高灵敏度的气体传感器，人们认为应该将这三个关键因素融合在一个传感器装置中。较少

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