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

The gas sensing properties of porous hot-wire MoS2 (hwMoS2) thin films have been studied. The films were deposited on oxidized silicon substrates by heating a molybdenum filament in a vacuum chamber in H2S environment. The samples remain at room temperature during the deposition and the grown films are amorphous and porous. Reversible changes of the current values in the hwMoS2 films were observed due to the presence or upon removal of chemical gases such as hydrogen (H2) and carbon monoxide (CO). The sensitivity, was dependent on the concentrations of the gases and the temperature of measurement. The response time was found to be comparable to the recovery time and of the order of a few seconds. It is important to note that the surface of the hwMoS2 films was not activated with any catalyst, which is a common practice in most thin films used for gas sensing, rendering our process simpler and cheaper.