Silicon Nanoporous Pillar Array Of Sno <sub> 2 </ Sub> Composite Films Alcohol Sensitivity

The porous silicon (Porous Silicon, PS) thin film sensor is a brand-new sensor technology which has developed along with the nanometer material practical application and the PS research from 1990s. Owing to the properties of large specific surface area, technological compatibility with the typical silicon arts, easy compound with many kinds of sensitive materials, it can satisfy people's demand to sensor's integration,intellectualization,multi-purpose request. The PS gas sensors and PS-based gas sensors have received much attention.We obtain a special porous silicon material which has peculiar pillar array structure by iron-passivated hydrothermally etching, we name it as Silicon Nanoporous Pillar Array (Si-NPA). The most notable structural features of Si-NPA not only makes it has large surface area, but also provides a very effective pathway for vapor transportation and convenient to efficient absorbing and desorbing of gas molecules. Therefore the Si-NPA has latent application value for gas sensor in view of its unique feature.Several topics studied in this thesis are listed below:1. Material preparation and characterization: The sensing properties of Si-NPA and SnO₂/Si-NPA under different condition have been studied. SEM,TEM,XRD, FT-IR were used to analyze and characterize the morphology and structure of Si-NPA and SnO₂/Si-NPA. The best condition of material preparation was found.2. Si-NPA-based sensor and test of it's sensing properties: Si-NPA-based gas sensor was studied in this chapter. First, sensors in which Si-NPA are used as the gas sensitive layer. Measurements are taken for acetone and ethanol vapor. However the responses of ethanol are better than those of ethanol. We also analyzed the relations in sensing characteristic and material structure.3. SnO₂/Si-NPA-based sensor and test of it's sensing properties: Ethanol sensors were made based on SnO₂/Si-NPA and the corresponding sensing properties...