Novel p-type gas sensing thin film based on Nb-Ti-O mixed oxides

Thin films with variable concentrations of niobium and titanium mixed oxides have been achieved by reactive sputtering process and p-type sensing layers have been achieved. Structural and morphological studies have been carried out by means of SEM, TEM and AFM in order to understand the measurement of sensing performance. The films proved sensitive to ethanol and carbon monoxide. It was also shown that annealing temperature and niobium content strongly influence the gas response of the films leading from n-type response typical of TiO/sub 2/ and the most of metal oxide sensors to p-type response and this peculiarity is crucial for the discrimination of different gases.