Gas Sensing Investigation of Porous Hot-wire Molybdenum Disulphide Thin Films

The aim of this research is to examine hot-wire molybdenum disulphide (hwMoS₂) thin films as sensory materials in chemical sensors. The samples remain at room temperature during the growth of films rendering hot-wire deposition suitable for polymeric substrates. For the test of the sensing properties, the hwMoS₂ films were packed in classic dual in-line packages (DIL) using the wire bonding technique. On the surface of the hwMoS₂ films a photoresist film was applied by spinning. Then interdigitated electrodes were opened followed by gold e-beam evaporation using titanium as adhesion layer. The sensing properties of the samples were tested using a home-made setup consisting of a small volume stainless steel chamber and a heater capable of reaching temperatures up to 500^oC. The gas concentrations were controlled by means of mass flow controllers. The sensors were stabilized in synthetic air before their exposure to gases (hydrogen, carbon monoxide, moisture, acetone etc). The current changes of the sensor were measured with an electrometer connected to a personal computer via a GPIB interface. This research is ongoing.