Gas-sensing characterization of TiO2-ZnO based thin film

In this work, we investigate gas sensing characteristics of a new composite material, ZnO doped TiO2. TiO2/ZnO layers have been deposited by ion-assisted e-beam evaporation with different doping concentrations. Structural and morphological characterization has been carried out by means of SEM, XRD and EDX in order to correlate structural properties with gas sensing behavior. Gas-sensing characterizations toward acetone, ammonia, ethanol, CO, and NO2 highlight interesting behavior for the layers tested. Low ZnO concentration (1%) increase responses toward acetone and ethanol while response toward CO, NO2, and ammonia are still low. However, high ZnO concentration (5-10%) decreases acetone and ethanol responses while CO, NO, and ammonia is almost diminished. In addition, ZnO:TiO2 exhibit good response at medium operating temperature of 300degC.