SnO2／Si-NPA复合薄膜气敏传感材料的酒敏特性研究

Research on Ethanol-sensing Properties of SnO_2/Si-NPA

应用匀胶旋涂和退火处理的方法将纳米级SnO2和具有规则阵列结构和多孔结构的硅微米/纳米结构复合体系硅纳米孔柱阵列(Si-NPA)进行很好地复合,对复合材料的电阻酒敏特性进行了测试。结果表明,SnO2/Si-NPA与Si-NPA相比对酒精具有更高的灵敏度和更好的长期稳定性SnO2/Si-NPA良好的酒精敏感性能被归因于复合薄膜材料既保持了衬底材料独特的微纳双重结构,又保证了SnO2能够发挥其在传感方面的作用,即高灵敏度来自于其巨大的比表面积对酒精分子的物理吸附和材料对酒精分子化学吸附。通过工艺条件的进一步改进以及气体标定系统和信号检出系统进行配套设计与优化,可望开发出性能优异的酒敏传感元件。

Ethanol sensors were made based on SnO2/Si-NPA and the corresponding sensing properties were investigated. As-prepared tin dioxide sol was spin-coated on Si-NPA and then sintered in oxygen ambient, both for SnO2 crystallization and strengthening the combination between tin dioxide and Si-NPA substrate. Silicon nanoporous pillar array （Si-NPA） is used as substrate which a novel silicon micron/nanometer structural composite system with both regular surface pillar array and porous structure, was prepared by hydrothermal etching method and its ethanol-sensing properties were measured. It was shown that SnO2/Si-NPA exhibited high sensitivity and short response time to ethanol. This excellent performance of Si-NPA to ethanol was due to its surface structure and excellent gas sensing properties of SnO2, i.e. , the high sensitivity originated from the physical and chemical adsorption brought by the large specific area and SnO2 , while the short response time come from the effective gas transportation pathway provided by the regular pillar array. The unique hierarchical structure of SnO2/Si-NPA might be applied in the field of silicon-based thin film sensors in future.