NOx gas sensing characteristics of WO3 thin films activated by noble metals (Pd, Pt, Au) layers
NOx gas sensing characteristics of WO3 thin films activated by noble metals (Pd, Pt, Au) layers
复制标题
DOI：
10.1016/s0925-4005(98)00156-7
复制
发表时间：
1998-07-15
影响因子：
8.4
通讯作者：
Cassano, G
中科院分区：
文献类型：
--
作者：
Penza, M;Martucci, C;Cassano, G
WO 3基气体传感器器件已经通过反应射频溅射在玻璃衬底上制造。将钯（Pd）、铂（Pt）、金（Au）贵金属（100-600埃）作为活化剂层蒸发到WO上，将薄膜和Al层（1500埃）溅射在它们的顶部作为传感器输出的上电极。发现所述传感元件在低温（100-300 ℃）下对NO和NO2气体具有优异的灵敏度。Pt、Pd和Au的最佳操作温度分别为150 ℃和200 ℃。在空气中存在低浓度NO（0-440 ppm）和NO2（0-10 ppm）气体的情况下，薄膜气体传感器的电阻可逆地增加。活化剂层对低温下对NOx的响应速度和对其它还原气体（CO、CH 4、H-2、SO 2、H2S、NH 3）的选择性增强具有促进作用。响应和恢复时间的温度依赖性已被检查。研究了贵金属层厚度对NOx气体灵敏度的影响。NO和NO2气体校准曲线已被记录为每个制造的传感器设备的最佳性能。(C)1998年Elsevier Science S.A. All rights reserved.
WO3-based gas sensor devices have been fabricated by reactive rf sputtering on glass substrates. Palladium (Pd), platinum (Pt), gold (Au) noble metals (100-600 Angstrom) were evaporated as activator layers onto WO, thin films and Al layers (1500 Angstrom) were sputtered on top of them as upper electrodes for sensor output. The described sensing element was found to possess excellent sensitivity towards NO and NO2 gases, at low temperatures (100-300 degrees C). The optimum operating temperature was 150 and 200 degrees C for Pt, Pd and Au, respectively. The resistance of the thin-film gas sensor increases reversibly in the presence of low concentrations of NO (0-440 ppm) and NO2 (0-10 ppm) gases in air. The activator layers have an promotional effect on the speed of response to NOx at low temperatures and on selectivity enhanced with respect to other reducing gases (CO, CH4, H-2, SO2, H2S, NH3). The temperature dependence of response and recovery times has been examined. The influence of the thickness of the noble metals on NOx gases sensitivity has been investigated. The NO and NO2 gases calibration curves have been recorded for the optimum performances of each fabricated sensor-device. (C) 1998 Elsevier Science S.A. All rights reserved.