Properties of Ga-Zn based mixed oxides for gas sensing applications

Gallium-Zinc mixed metal oxides have been fabricated by the sol-gel process and tested towards oxygen gas. These films were deposited on alumina transducers with interdigital electrodes for gas sensing measurements and on single crystal silicon substrates for microcharacterization. X-ray Photoelectron Spectroscopy (XPS) and Rutherford Backscattering Spectrometry (RBS) showed that the actual concentrations in Ga-Zn oxide thin films differ from the nominal values in the prepared solutions as a function of annealing temperature. Furthermore, the concentration of Zn decreases with a rise of sample annealing temperature. It was found that by increasing the amount of Zn in the sensor film, the operating temperature decreased as well as the base resistance.