NOx gas detection characteristics in FET-type multi-walled carbon nanotube-based gas sensors for various electrode spacings

• Published in: Journal of the Korean Physical Society Vol. 68; no. 6; pp. 797 - 802
• Main Authors: Kim, Hyun Soo, Jang, Kyung Uk, Kim, Tae Wan
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.03.2016; 한국물리학회
• Subjects: Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; 물리학; MWCNT; Gas sensor; FET-type; Arrhenius plot
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.68.797

In this study, we fabricated a p-channel FET-type NO x gas sensor by using multi-walled carbon nanotubes (MWCNTs). Carbon nanotubes (CNTs) have good electronic, chemical-stability, and sensitivity characteristics. In particular, gas sensors require characteristics such as high speed, selectivity, and sensitivity. The fabricated sensor was used to detect NO x gas for different values of the gate-source voltage (V gs ) and the electrode spacings (30, 60, 90, and 120 μ m). The gas sensor that absorbed NO x gas molecules showed a decrease in resistance. The sensitivity of the gas sensor was increased by increasing the electrode spacing. Additionally, while changing the Vgs and the temperature inside the chamber for the MWCNT gas sensor, we obtained the sensitivity and the normalized response for detecting NO x gas. We also obtained the adsorption energy (U a ) by using Arrhenius plots based on the reduction of resistance due to voltage variations. The adsorption energy was found to increase with increasing applied voltage.