The Manufacture Of Gas Sensor Based On Sybac Effect

The preparation of material is critical to fabrication of gas sensor made from semiconductor. Nanometer WO₃ was synthesized in a new designed instrument by gas-state reaction with tungsten filament.By XRD,SEM and TEM, we investigated the structure and surface morphologies and researcher on the relationship between structure and sensing properties of gas sensing materials. The conclusion is sensing properties of the component completely decided by its microstructure. The component made from smaller particles with rough surface is more sensitive them the one made from bigger particles with smooth surface. I believe that rough surface is more active than smooth surface when reacting to gas.Furthermore, we designed a new type gas sensor based on Sybac effect.Then we made nanometer WO₃ into these type gas sensors. Each of them can afford a direct voltage ranging from 0-100mV. The gas sensing measurement results revealed that these sensors have a certain response to NO₂ with good response characteristic. To 20×10^-6 NO₂,with good response time of 5s and recovering timeof 16s, the sensitivity is 13 and changes with the density of NO₂. So the conclusion is that this gas sensor based on Sybac effect is aprospective gas sensor of new type.