|
Metal oxide materials for solid state gas sensors has attracted lots of attention in the past few decades due to its low fabrication cost, small device size and potential application in toxic gases detection. SnO2 is one of the favorable materials since it has outstanding performance towards the detection of various gases. Its sensing mechanism in brief was based on the change in charge carrier density of the materials due to the presence of gas molecules and the change was determined by measuring the resistance or capacitance. Despite of its great success, researches has continue to further optimize the selectivity, sensitivity, response time and more importantly lowering the working temperature of the material. In this work, SnO2 nanostructures with metal nanoclusters on the surface was prepared. The incorporation of different metal nanoclusters would offer feasibility on the selection of gas detection. The energy level alignment and the Schottky barriers at the metal-metal oxide interface would further improve the sensitivity and response time of the materials. The surface plasmon generated by the metal nanoclusters utilizing visible light could lower the operation temperature and enhance sensitivity by offering more charge carriers. The SnO2 nanofiber in this work was prepared by a scalable electrospinning method and the Ag and Au nanoclusters were prepared by sputtering or thermal evaporation. Effect of the SnO2 morphology, size and distribution of the metal nanoclusters and the illumination on the device performance will be investigated and the detail working mechanism will be discussed.
|
