介孔硅基WO3纳米颗粒薄膜室温气敏元件特性

采用双槽电化学腐蚀法在p＋单晶硅片表面制备介孔硅层（meso-PSlayer）,然后用对向靶磁控反应溅射法在介孔硅表面沉积WO3纳米颗粒薄膜,在干燥空气中于400℃下保温4h进行退火热处理,制备出介孔硅基WO3纳米颗粒薄膜（WO3-PS）室温气敏元件.利用扫描电子显微镜（SEM）分析介孔硅层及WO3-PS的表面形貌,通过X射线衍射（XRD）研究WO3的结晶状态,测试WO3-PS气敏元件在室温下对NO2、NH3的气敏性能,并探讨了WO3-PS气敏元件的工作机理.实验结果表明,在介孔硅表面沉积WO3纳米颗粒薄膜可使介孔硅的气敏性能显著提高,其中在室温下对10×10^-6NO2的灵敏度由5提高至56,大大提高了介孔硅的灵敏度,并降低了其响应/恢复时间,提高了对NO2的选择性.

Meso-Porous Silicon-Based WO_3 Nano-Particle Film Gas Sensor Operating at Room Temperature

Meso-porous silicon (meso-PS) layers were fabricated by electrochemical dissolution in a double-tank cell on the surface of the single-crystalline p~+-type silicon. Then, WO_3 nano-particle films were deposited on meso-PS layers by dc facing target reactive magnetron sputtering method. After deposition, the samples were annealed in dry air at 400 ℃ for 4 h. The meso-porous silicon-based WO_3 nano-particle film (WO_3-PS) gas sensors were fabricated. The surface morphologies of meso-PS layers and WO_3-PS films were characterized by scanning electron microscope (SEM). The crystallization was studied by X-ray diffraction (XRD). Also the NO_2 and NH_3 gas-sensing properties of WO_3-PS gas sensor were thoroughly measured at room temperature. It can be concluded that meso-PS gas sensors presents much higher sensitivity after deposited with WO_3 nano-particle film. The gas sensitivity to 10×10~(-6) NO_2 at room temperature can reach 56 from 5; meanwhile, the WO_3-PS gas sensors show quicker response time and higher selectivity to NO_2 than meso-PS gas sensors.