| 1. |
- Wen, Chenyu, et al.
(författare)
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Assessing kinetics of surface adsorption-desorption of gas molecules via electrical measurements
- 2016
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 223, s. 791-798
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Tidskriftsartikel (refereegranskat)abstract
- Gas sensing represents a grand research and application field. Owing to their unique structure of single-atom/molecule thickness, the emerging two-dimensional (2D) semiconductors are anticipated to display ultrahigh sensitivity capable of detecting minute changes in surface charge. To support the vast variety of gas sensing applications for domestic gases and environmental control, rapid and reliable quantitative analysis of measurement results based on established sensing mechanism and kinetics is essential. The present work uses graphene-based 2D sensors as a model system to establish the analytical capability for assessing the adsorption-desorption kinetics of gas molecules via electrical characterization. By linking the electrical current in graphene to the surface coverage of gas molecules and by incorporating the non-steady-state initial conditions for adsorption and desorption, an analytical model is established. Important kinetic parameters including activation energy, equilibrium coverage and adsorption-desorption time constants are obtained. The model can also facilitate real-world applications in gas sensing.
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| 2. |
- Ye, Qiangqiang, et al.
(författare)
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Ultra-Sensitive and Responsive Capacitive Humidity Sensor Based on Graphene Oxide
- 2015
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Ingår i: Proceedings of 2015 ieee 11th international conference on ASIC (ASICON). - : IEEE. - 9781479984855
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Konferensbidrag (refereegranskat)abstract
- Humidity sensors have attracted extensive attentions due to their various applications in environment monitoring, health care and internet of things. Graphene oxide has recently been exploited as a humidity sensing material because of its good hydrophilicity and excellent sensitivity. Here we report an ultra-sensitive and responsive capacitive humidity sensor using graphene oxide as sensing material. A capacitance change of ten times is observed when the relative humidity changes from 50% to 90%. The response and recovery time of the sensor are measured to be 0.066 and 0.154 s, respectively, which are several orders of magnitude shorter than conventional humidity sensors. Furthermore, its responses to flow rate, temperature and other vapors are also characterized.
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