Ammonia Gas Sensing Using Porous silicon

• Published in: Journal of physics. Conference series 2024-10, Vol.2857 (1), p.12051
• Main Authors: Salman, Seham H., Jahil, Sarab S., Hassan, N. A., Abbas, Shaimaa A., Jasim, Kareem A.
• Format: Article
• Language: English
• Subjects: Ammonia; Electrochemical etching; Etching; Gas Sensing; Gas sensors; Operating temperature; Porous silicon; Sensitivity; Time measurement
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2857/1/012051

Psi prepared by Electrochemical etching technique at invariable etching current density of 10 mA/cm 2 and at different times (7 and 17) min. The porous Si structure was studied using XRD, (FE-SEM) and EDS. The process of sensing NH 3 gas is carried out at different operating temperatures (R.t,80,130 and 200)°C and the gas concentration is constant. It is measured by changing the resistance of the sensor as a function of exposure time to the gas. The result showed the XRD patterns of the PS at (7 and 17) min etching time. the peak samples at (111) around 2θ = 28.5°. It is observed that the peak intensity declines with rising the etching time, and some structural parameters for porous silicon are calculated. From FE-SEM, the images show the sample prepared in (7 and 17) min with the depth of (6.18 12.82) μm, with a size of about 50 nm. Porous silicon that was produced in a time of 17 min has a higher sensitivity to NH 3 gas than that of the sample that was produced in a time of 7 min. It was found that when the operating temperature changes from (R.T -200C°), the sensitivity of the samples changes with the stability of the etching time. The PSi sample (17 min) has a high sensitivity for NH 3 gas at room temp.