ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique with various thicknesses (5, 10, 15 μm). The morphology of the sensing films was analyzed by SEM and EDS analyses. The gas sensing characteristics to ethanol (25-250 ppm) were evaluated as a function of film thickness at 400°C in dry air. The relationship between thickness and ethanol sensing characteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes were investigated. The effects of film thickness, as well as the cracking phenomenon, though, many cracks were observed for thicker sensing films. Crack widths increased with increasing film thickness. The film thickness, cracking and ethanol concentration have significant effect on the sensing characteristics. The sensing characteristics with various thicknesses were compared, showing the tendency of the sensitivity to ethanol decreased with increasing film thickness and response time. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusively and reactivity of the gases inside the oxide films. The thinnest sensing film (5 μm) showed the highest sensitivity and the fastest response time (within seconds).
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机译：ZnO纳米颗粒是通过使用环烷酸锌作为前体溶解在甲苯/乙腈（80/20体积％）中的火焰喷雾热解法（FSP）制备的。通过XRD，BET和HR-TEM分析颗粒性质。通过将颗粒混合到由萜品醇和乙基纤维素作为载体粘合剂的有机糊剂中来制备感测膜，并通过刮刀技术制造各种厚度（5、10、15μm）的感测膜。通过SEM和EDS分析来分析感测膜的形态。在400℃干燥空气中，对乙醇（25-250 ppm）的气敏特性作为膜厚度的函数进行了评估。研究了与Au电极交叉的Al 2 O 3 衬底上ZnO厚膜的厚度与乙醇感测特性的关系。但是，膜厚和开裂现象的影响，对于较厚的传感膜观察到许多裂纹。裂纹宽度随膜厚的增加而增加。膜厚，破裂和乙醇浓度对传感特性有重要影响。比较了各种厚度的感测特性，显示出对乙醇的敏感性随膜厚度和响应时间的增加而降低的趋势。基于氧化膜内部气体的扩散性和反应性，讨论了气敏特性与膜厚之间的关系。最薄的感测膜（5μm）显示出最高的灵敏度和最快的响应时间（几秒钟内）。
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