Search

Your search keyword '"Gupta, S. K."' showing total 3 results
Start Over Author "Gupta, S. K." Topic gas detectors Topic nanowires
3 results on '"Gupta, S. K."'

1. H2S DETECTION BY CuO NANOWIRES AT ROOM TEMPERATURE.

Author

KAUR, MANMEET, GANAPATHI, KAILASA, DATTA, NIYANTA, MUTHE, K. P., and GUPTA, S. K.

Subjects
*HYDROGEN sulfide, *COPPER oxide, *NANOWIRES, *TEMPERATURE effect, *GAS detectors, *METAL foils, *CRYSTAL growth
Abstract

Room temperature gas sensing properties of CuO nanowires synthesized by thermal oxidation of copper foils was studied in different configurations: (i) isolated nanowires aligned between two electrodes, (ii) as grown CuO foil consisting of nanowires and (iii) CuO nanowire films. Sensors were studied for response to different gases. Different sensors showed qualitatively different response on exposure to H2S. Isolated nanowires showed high sensitivity, (~200% for 10 ppm of gas) and fast response (30 s) and recovery times (60 s). In these samples, the resistance mainly decreased on exposure to H2S (though a small initial increase was observed). In CuO foils, resistance increased for low concentrations (5-10 ppm) but decreased at high concentrations. In the case of CuO nanowire films, resistance only increased on exposure of H2S (upto 400 ppm). Since CuO is a p-type semiconductor, on exposure to H2S an increase in resistance is expected due to oxygen adsorption related process. Decrease in resistance in some of the sensors was understood in terms of reaction of CuO with H2S resulting in the formation of CuS. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

2. ZnO nanowires coated with CuO films as highly sensitive H2S sensors.

Author

Datta, Niyanta, Ramgir, N. S., Kaur, Manmeet, Debnath, A. K., Aswal, D. K., and Gupta, S. K.

Subjects
*ZINC oxide, *NANOWIRES, *METAL coating, *COPPER oxide, *THIN films, *GAS detectors, *THICKNESS measurement
Abstract

The gas sensing characteristics of ZnO nanowires (NWs) coated with different thickness of CuO film have been investigated. ZnO NWs were grown on Si/SiO2 by hydrothermal method and CuO films were deposited by thermal evaporation. It has been found that ZnO NWs exhibit characteristic n-type behavior upto a CuO thickness of 50 nm; whereas at higher thickness the samples show p-type behavior (typical of CuO). At a CuO thickness of 10 nm the sensitivity towards H2S was 500% more as compared to pure ZnO NWs films. In addition, the operating temperature was reduced to 200°C. [ABSTRACT FROM AUTHOR]

Published
2012
Full Text
View/download PDF

3. Growth And Gas Sensing Properties Of Dielectrophoretically Isolated CuO-W18O49 Heterostructures.

Author

Jain, Chhavi, Mukund, Vignesh, Kaur, Manmeet, Ganapathi, Kailasa, Ramgir, Niranjan S., Datta, Niyanta, Aswal, D. K., and Gupta, S. K.

Subjects
*HETEROSTRUCTURES, *CRYSTAL growth, *GAS detectors, *NANOWIRES, *DIELECTROPHORESIS, *COPPER oxide, *TUNGSTEN oxides, *METAL oxide semiconductors
Abstract

Hierarchical heterostructures consisting of W18O49 nanowires grown on CuO nanowires have been prepared and studied for their gas sensing properties. SEM images show that W18O49 initially grow as an shell over core CuO nanowire with protusion like branches whose thickness depends on oxygen partial pressure. These CuO:W18O49 structures were dielectrophoretically isolated and studied for their gas sensing properties. The results show potential of use of tailored hierarchical heterostructures for the fabrication of gas sensors. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results