Impedance characterization of Te based gas sensitive films

Abstract

Gas sensing performance of Te films investigated by method of impedance spectroscopy is reported and discussed. The films have been prepared by thermal vacuum evaporation onto sintered alumina (Al2O3) substrates with a priory deposited platinum interdigital electrodes. The morphology of the films appears to consist of interconnected islands and dots, which facilitate the solid-gas interaction. It is shown that impedance spectra are strongly influenced by gaseous environment. Analyses of complex impedance spectra allowed evaluating of some physical parameters of the films, in both dry air and its mixture with hydrogen, nitrogen dioxide and hydrogen sulphide taken as target gases. The interfering sensitivities to these gases at room temperature have been assessed.