| 1. |
- Andersson, Mike, 1977-, et al.
(author)
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Detecting non-hydrogen containing species with field effect devices
- 2008
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In: IEEE Sensors,2008. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 1320-1323
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Conference paper (peer-reviewed)abstract
- An investigation of the influence and role of oxygen in the detection of non-hydrogen containing substances with Pt/SiO2/SiC based MOS field effect sensors, employing new model systems, has been carried out. With the use of a novel intermediate layer, by which the direct influence of hydrogen on the sensor response can be markedly reduced, the part of the sensor response which is not directly related to hydrogen (which to a small extent is always present in any gas mixture) could be resolved. The Pt/SiO2 NO reduction/oxidation model system has also been studied from a sensor perspective and the results compared to spectroscopic and mass spectrometry studies of the surface reactions from the field of catalysis. The results support the hypothesis from earlier work that the removal of oxygen from the sensor surface (e.g. by oxidation reactions with CO or NO) to a certain extent directly is involved in the detection of non-hydrogen containing species.
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| 2. |
- Andersson, Mike, 1977-, et al.
(author)
-
In situ DRIFT study of the CO response mechanism of MISFET sensors using Pt/SiO2 model sensor
- 2008
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In: Proceedings of IEEE Sensors. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 1309-1312
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Conference paper (peer-reviewed)abstract
- The temperature dependence of the sensor response towards CO of SiC-FET sensors has been studied by combining in situ DRIFT spectroscopy and sensor response measurements. The DRIFT spectroscopy studies have been performed on a model sensor representing the top layer of a SiC-FET sensor with porous Pt gate. Adsorbates on the model sensor have been studied at varying temperatures and gas concentrations, and correlated to sensor response measurements at similar experimental conditions. The results show that the temperature dependence partly can be correlated to the CO coverage of the surface. The switching point of the sensor response, observed at different temperatures depending on the CO and oxygen concentrations is well in accordance with the kinetics of the CO oxidation reaction.
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| 3. |
- Khranovskyy, Volodymyr, 1979-, et al.
(author)
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Oxygen absorption effect on the sensitivity and material stability of ZnO nanostructured films
- 2008
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In: Proceedings of IEEE Sensors. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 874-877
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Conference paper (peer-reviewed)abstract
- In this work the effect of ambient influence on the electrical conductivity of ZnO films has been studied. Nanostructured ZnO films (undoped and Ga, Co, Mn doped) were exposed to oxygen (1-80 vol.%) at temperature range 300-500degC. A dominant effect of ambient influence via oxygen absorption was observed: the intensity of conductivity decrease was found to be proportional with temperature and tends to saturation with time. After oxygen saturation the reversible effect of oxygen adsorption became dominant and contributed to the films conductivity. Oxygen exposed undoped ZnO films revealed high sensitivity for oxygen content change in the ambience, therefore they have been further processed for gas sensor fabrication.
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