Electrical impedance analysis of ZnO thin films for ammonia gas sensors
NOPR - NISCAIR Online Periodicals Repository
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Title |
Electrical impedance analysis of ZnO thin films for ammonia gas sensors
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Creator |
Mariappan, R.
Dinagaran, S. Srinivasan, P. Vijayakumar, S. |
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Subject |
ZnO device
Impedance analysis Ammonia sensor |
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Description |
483-491
The electrical impedance analysis of the ZnO films has been performed using complex impedance spectroscopy in the frequency range from 100 Hz to 1 MHz with temperature change from 70 to 175℃. Combined impedance and modulus plots have been used to analyse the sample behaviour as a function of frequency at different temperatures. Temperature dependence of ac conductivity indicates that the electrical conduction in the material is a thermally activated process. The frequency dependence of the ac conduction activation energy is found to obey a mathematical formula. It is concluded that the conductivity mechanism in the ZnO sensor is controlled by surface reaction. The operating temperature of the ZnO gas sensor is 175℃. The impedance spectrum also exhibited a decreased semicircle radius as the ammonia concentration is increased from 50 to 500 ppm. In addition, the impedance spectrum also exhibited a decreased semicircle radius with the exposure time increase from 0 to 20 min thereafter slightly increased. Impedance spectroscopy analysis has shown that the resistance variation due to grain boundaries significantly contributed to the gas sensor characteristics. |
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Date |
2023-07-11T05:33:54Z
2023-07-11T05:33:54Z 2023-07 |
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Type |
Article
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Identifier |
0975-0991 (Online); 0971-457X (Print)
http://nopr.niscpr.res.in/handle/123456789/62284 https://doi.org/10.56042/ijct.v30i4.71226 |
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Language |
en
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Publisher |
NIScPR-CSIR,India
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Source |
IJCT Vol.30(4) [July 2023]
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