Describing the effect of Ag/Au modification on operating temperature and gas sensing properties of thick film SnO2 gas sensors by gas diffusion theory

S. Mohammad Yousefi | Saeideh Rahbarpour | H. Ghafoorifard

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=116552
Date :  2019/04/01
Publish in :    Materials Chemistry and Physics
DOI :  https://doi.org/10.1016/j.matchemphys.2019.02.010
Link :  https://www.sciencedirect.com/science/article/abs/pii/S0254058419301051
Keywords :Gas diffusion theory, SnO2 gas sensor, Au nanoparticle, Ag nanoparticle, Sensor modification.

Abstract :

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The effect of Ag and Au additives on the optimum operating temperature and response level of thick film SnO2 gas sensors is investigated and compared with the results of pure SnO2 ones. Fabricated samples were examined at various atmospheric conditions and at different operating temperatures (130 to 400 °C). It is shown that compared with pure SnO2 samples, in Ag-SnO2 samples 50 °C reduction of operating temperature and 7 times increase of response level is achieved. The achieved modifications are 70°C reductions in operating temperature and 4 times increase of response level for Au-SnO2 samples. In addition to reporting the improving properties of SnO2 samples by adding Ag and Au, the validity of the gas diffusion model was also verified in these metal added samples for the first time. Gas diffusion theory is a comprehensive theory which its validity in resistive gas sensors has been verified by many researchers. The parameters of gas diffusion model were extracted for all fabricated sensors to achieve better understanding of their sensing properties.