PEG/WCl6添加比例对WO3薄膜形貌及气敏特性的影响

以氯化钨(WCl₆)、无水乙醇(C₂H₅OH)和二甲基甲酰胺(C₃H₇NO)为前驱体，以聚乙二醇(PEG-1000)为造孔剂，采用非水解溶胶-凝胶法制备WO₃多孔薄膜，考察了PEG与WCl₆添加比例对薄膜形貌结构和气敏特性的影响.结果表明，在PEG与WCl₆添加比例为0.5时可获得形貌均一、孔隙率高、比表面积大的WO₃多孔薄膜.所获WO₃薄膜具有单一的单斜晶系结构，主要由直径为20~60nm的纳米颗粒所构成.气敏特性研究结果表明，WO₃多孔薄膜呈现n型半导体特性，在最佳工作温度100℃时表现出对NO₂良好的气敏性能；WO₃薄膜的成膜机理表明，造孔剂PEG-1000引导无机材料形成高孔隙率和高比表面积的三维多孔薄膜结构，该多孔结构有望作为NO₂气体的潜在气敏材料.

Influence of PEG/WCl6 Ratio on the Morphology and Gas Sensing Properties of WO3 Thin Films

WO₃ thin films were synthesized by a non-hydrolytic sol-gel(NHSG)method in the presence of WCl₆， C₂H₅OH and C₃H₇NO as the precursor as well as the PEG-1000 as the pore former. The influence of PEG/WCl₆ ratio on the morphology and gas sensing properties of WO₃ thin films were investigated.It is shown that WO₃ thin films with uniform morphology， high porosity and large specific surface area were obtained at the PEG/WCl₆ ratio of 0.5. The obtained thin films have a single monoclinic crystal structure and consist of WO₃ crystalline nanoparticles with the diameters of 20~60nm. The gas sensing measurements indicate that WO₃ thin films show n-type semiconductor characteristics and demonstrate excellent gas sensing properties at the optimal operation temperature of 100℃. The film formation mechanism of WO₃ thin films indicates that PEG-1000 may induce the inorganic material to form a three-dimensional porous film structure with high porosity and large specific surface area. The obtained WO₃ porous films are potential sensing materials for the detection of NO₂.