Speaker
Description
In this work, we study the advantages of two advanced sputtering techniques for the preparation of a nanostructured thin-film conductometric gas sensor. We combined tungsten oxide (WO3) thin films with other materials to achieve enhanced sensory behavior towards hydrogen. Thin films of WO3 were prepared by the HiPIMS technique and annealed in air at moderate temperature (350 °C). By tuning the deposition parameters of reactive high-power impulse magnetron sputtering, specifically the pulse length, we were able to prepare WO3−x films with various stoichiometry and structure. To characterize the sensory behavior of the films, the tungsten oxide films were decorated by Pd nanoparticles before annealing and were assembled as a gas sensor. We demonstrate that the stoichiometry of the as-deposited films influences considerably the type of crystalline phase formed in the annealed films. The appropriate sub-stoichiometry of the films (approx. WO2.76) enabled crystallization of the monoclinic phase during the annealing
The specimens were tested for the response to a time-varied hydrogen concentration in synthetic air at various temperatures. The sensitivity and response time were evaluated. The performance of individual films is presented as well as the details of the synthesis. The sensory response of the films that crystallized in the monoclinic structure was proven to be superior to that of the films containing other phases.
| Speaker Country | India |
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