Ozone Sensing Properties of Polycrystalline Indium Oxide Films at Room Temperature

Abstract

The room temperature ozone sensing properties of polycrystalline indium oxide (InO x ) thin films have been investigated. Films with thicknesses of 10 to 1100 nm were sputtered in a dc-magnetron system onto Corning 7059 glass at various substrate temperatures and sputtering atmospheres. Initially, as-grown films were brought to a high conducting state through a photoreduction process by UV light exposure and subsequently they were exposed to a controlled ozone atmosphere. By this treatment the sensitivity of the films could be monitored. The films exhibit resistivity changes of more than five orders of magnitude. The sensitivity was studied for different ozone concentrations and at different temperatures. The response of the films increased linearly with the ozone concentration and the highest sensitivity was achieved when the measurements were carried out at room temperature. Best results were achieved with very thin InO x films (< 100 nm) deposited at room temperature in a pure oxygen atmosphere.

Zinc oxide as an ozone sensor

“…Their sensitivity was determined by irradiating them with an ultraviolet ͑UV͒ light [mercury pencil lamp from Edmund Scientific having an average intensity of 4 mW/cm 2 (0.5 mW/ cm 2 for the ac measurements) at a wavelength of 254 nm] for 20 min. They were then subjected to oxidation in ozone for 50 min, with online dc and ac impedance monitoring, using a chamber described elsewhere, 27 where the backing pressure was of 1.06 Pa. For the dc conductivity measurements, a 617 Keithley electrometer computer controlled was used. The ac impedance measurements were performed using a precision impedance analyzer (Agilent 4294 A) in the frequency range from 40 Hz to 110 MHz in 201 steps, before and after UV exposition, using the same electrodes and configuration described above.…”

Impurity Centers in Oxides Investigated by γ-γ Perturbed Angular Correlation Spectroscopy and <i>Ab Initio</i> Calculations

“…Indium oxide (In 2 O 3 ) is a very important material for microelectronic applications [74]. It is widely used as a material for transparent electrodes in electronic devices such as liquid crystal displays [75], solar cells [76], as a barrier layer in tunnel junctions [77], as a sensing material in gas sensors [78] and in nanowire technology [79]. In 2 O 3 occurs in the bixbyite structure, body-centered cubic (bcc, Ia 3 , a=10.117 Å).…”

Atomic fluorine in cobalt trifluoride thermolysis

“…For these reasons, we took into account only the information concerning the change in the surface layer composition dependent on the conditions of their formation. The validity of this approach was demonstrated in the investigation of indium oxide films, InO x [15]: measured n(F)/n(Co(O)/n(F)/n(Co(In) ratios exceeded stoichiometric ones, but followed correctly the films composition dependence on the oxygen pressure.…”