Thin-Film Oxide Materials for Ozone Detection in Thermal Modulation Mode

This paper presents data on ozone detection. The purpose of this work was to find materials offering selectivity in analysis for ozone in air by examining the shape of the resistive response of some thin-film oxide semiconductor sensors operated in thermal modulation mode. For this purpose, thin Pd, Cd, Zn, and W metal layers were produced by sputter deposition on polycrystalline alumina (Al2O3) test structures with Pt electrodes for electrical resistance measurements. Next, the metallic layers were oxidized in air at a temperature of 550°C. The thickness of the resultant PdO, CdO, ZnO, and WO3 oxide films was ~30 nm. The resistive response of the thin-film PdO, CdO, ZnO, and WO3 oxide materials was measured in an ozone–air atmosphere in thermal modulation mode. The temperature of the sensors was varied sinusoidally between 50 and 300°C, and the ozone concentration in air was varied from 25 to 250 ppb. The use of thermal modulation made it possible to reveal differences in the shape of the response between the sensors at different ozone concentrations. The PdO sensor differs significantly in the shape of the resistive response from the other sensors. This characteristic feature of this material opens up the possibility of improving the selectivity of ozone detection with a PdO oxide sensor.