Development of ITO thin film sensor for the detection of formaldehyde at room temperature

Abstract Thin films of indium tin oxide were grown by the direct evaporation technique. The sensors fabricated under the optimized deposition conditions were exposed at room temperature (303 K) to different concentrations of formaldehyde vapours and the relative change in resistance was measured. The effect of the film thickness on the response to test vapours was studied. In order to enhance the sensitivity, sensors with thin promoting layers of different metals and oxide like Cu, Ag and MgO deposited on the top of the film were fabricated and tested. The sensors with improved sensitivity were studied for the elaborate response to formaldehyde vapours at room temperature.