1. Humidity and CO2 gas sensing properties of double-layer graphene.
- Author
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Fan, Xuge, Elgammal, Karim, Smith, Anderson D., Östling, Mikael, Delin, Anna, Lemme, Max C., and Niklaus, Frank
- Subjects
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CARBON dioxide detectors , *GRAPHENE synthesis , *HUMIDITY , *SEMICONDUCTORS testing , *METALLIC oxides - Abstract
Graphene has interesting gas sensing properties with strong responses of the graphene resistance when exposed to gases. However, the resistance response of double-layer graphene when exposed to humidity and gasses has not yet been characterized and understood. In this paper we study the resistance response of double-layer graphene when exposed to humidity and CO 2 , respectively. The measured response and recovery times of the graphene resistance to humidity are on the order of several hundred milliseconds. For relative humidity levels of less than ∼3% RH, the resistance of double-layer graphene is not significantly influenced by the humidity variation. We use such a low humidity atmosphere to investigate the resistance response of double-layer graphene that is exposed to pure CO 2 gas, showing a consistent response and recovery behaviour. The resistance of the double-layer graphene decreases linearly with increase of the concentration of pure CO 2 gas. Density functional theory simulations indicate that double-layer graphene has a weaker gas response compared to single-layer graphene, which is in agreement with our experimental data. Our investigations contribute to improved understanding of the humidity and CO 2 gas sensing properties of double-layer graphene which is important for realizing viable graphene-based gas sensors in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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