• Journal of the Semiconductor & Display Technology
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• v.11 no.1
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• pp.55-59
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• 2012

NOx is one of the toxin gases, which is mainly causing the optic-chemical smog phenomena, and decreasing in the function of nose and taste. Especially, NO is easily reacting with $O_3$, and then becoming the $NO_2$. $NO_2$ is mainly causing the acidulation rain. So, we should develop the NOx gas sensing system to detect NOx gas. In this paper, we present the microstructure and the NOx gas detecting properties of the nitrocellulose/MWCNT thin film coated by the air-spray on the glass substrate. The nitrocellulose/MWCNT-based gas sensors have been studied detecting NOx molecules of a ppm-level at the temperature range of $30{\sim}120^{\circ}C$. The resistance of the sensors decreases when the sensors are exposed to NOx gas. As a results, we obtained the nitrocellulose/MWCNT sensors with the sensitivity of 0.6%/sec under the 0.8 ppm of NOx gas concetration. Also, we get the activation energy of 0.202eV from the sensor for the 0.3 ppm of NOx gas concentration.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.117-121
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• 2010

The composite films were fabricated by air-spray method under the 2 kgf/$cm^2$ pressure using the multi-walled CNTs solution and the nitrocellulose on a 10 ${\mu}m$ polyimide film substrates. We obtained the composite films which were sprayed with the MWCNT dispersion by varying the spray time from 20, 40 and 60sec. The electrical and the optical properties of the sandwiched-structure-composite thin films were investigated by an UV/VIS spectrometer and a Hall Effect equipment. As a result, the optical transmittance of all thin films in the visible range, as well as the electrical conductance shows an available value for the transparent electrode. The carrier concentration and the light transmittance rate for the fabricated sample are between $3.733{\times}10^{10}$ and $6.551{\times}10^{14}cm^{-3}$, around 35 to 95%, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.290-296
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• 2011

Carbon nanotubes (CNTs) have excellent electrical, chemical stability, mechanical and thermal properties. In this paper, networks of Multi-walled carbon nanotube (MWCNT) materials were investigated as a resistive gas sensors for the $H_2$ gas detection. Sensor films were fabricated by the air spray method using the multi-walled CNTs dispersion solution on the glass substrates cured with plasma and nitrocellulose. Sensors were characterized by the resistance measurements in the self-fabricated oven in order to find the optimum detection properties for the hydrogen gas molecular. The sensitivity and the linearity of the MWVNT sensors using the glass substrate cured with plasma for the $H_2$ gas concentration of 0.06~0.6 ppm are 0.013~0.097%/sec and 0.131~0.959%FS, respectively. The MWCNT film was excellent in the response for the hydrogen gas moleculars and its reaction speed was very fast, which could be using as hydrogen gas sensor. The resistance of the fabricated sensors decreases when the sensors are exposed to $H_2$ gas.