| Autor: |
Anisimov, O. V., Gaman, V. I., Maksimova, N. K., Mazalov, S. M., Chernikov, E. V. |
| Předmět: |
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| Zdroj: |
Semiconductors; Jun2006, Vol. 40 Issue 6, p704-709, 6p, 5 Graphs |
| Abstrakt: |
A simple model of a resistive thin-film sensor is used to derive an analytic expression that describes the dependences of the response to the effect of reducing gas on temperature, partial gas pressure, the concentration of donor impurity in the SnO2 film, and the duration of the exposure to gas. An analysis of experimental data showed that the processes of adsorption and desorption of H2 molecules at T < 510 K are mainly controlled by adsorption centers occupied by oxygen in the form of O, while the centers with O− control these processes at T > 563 K. At T ≥ 510 K, the methane molecules interact with the centers occupied by O−. The desorption-activation energies are determined in a wide temperature range using the data on the time dependences of the response. This energy equals 0.36 eV for hydrogen at T < 510 K. At T > 563 K for hydrogen and T > 510 K for methane, the desorption-activation energy is equal to 1.3 eV. The adsorption-activation energy is equal to 2.5 eV for methane. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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