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Essay On Gas Sensor Technology

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Gas sensor technology is very appreciating in industries and defense since it possesses high sensitivity in gas detection. The most important challenges in transportable devices are sensitivity, selectivity, durability and low power consumption. To solve the selectivity problems, GBISs have been introduced. These latter are able to identify unknown gas’ ionization breakdown voltage. To reduce the breakdown voltage CNT-GBISs are employed [6]- [12] while others studies used MWCNT with a reduction of 100-450V.Nevertheless, these CNT-GBISs are exposed to corona discharges which lead to heat generation and may affect the gas ionization breakdown. For uniform fields, the breakdown characteristics are explained by Townsend's criteria (equ 1) [1]. …show more content…

Thus the objective of this paper is to overcome this limitation by providing a simple and low-cost fabrication. Nonorganic species ionization feature is also required.
Freestanding nanowire arrays are good field ionization sources since they present high aspect ratio and density. The template–assisted electromechanical method is an easy and costless technique but presents limitations as the incorporated nanowires arrays bundle or collapse during template removal. To prevent this a PAA growth AuNWs were vertically aligned and embedded at a miniature cylindrical cell with a flat cathode. A number of tests gases have been used to perform the field-ionization’s tests with deviating low ionization threshold voltages (Vi) as results.
Literature review
Fig. 1(b) shows the electron tunneling into the valence band with an increase of the effective work function, and the expression of the critical distance changes as shown by equation (3). The critical distance now depends on the amount of band bending whose expression is shown by equation (4). Even with zero fields, authors [19],[24]-[27] have demonstrated that impurities and dangling bonds may impact the band bending potential. With an applied field reduction of the band, bending is observed with a tunneling above the Fermi level even with an absence of inversion. [25] states that the critical distance is controlled by the changing the Fermi level. Note that the small critical is yield by a

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