Highly sensitive NO2 sensor device featuring a JFET-like transducer mechanism
| Autor: | Harald Böttner, Claus-Dieter Kohl, Ulrich Hoefer, Elmar Wagner |
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| Rok vydání: | 1998 |
| Předmět: |
Materials science
Diffusion Schottky barrier Metals and Alloys Analytical chemistry Conductance chemistry.chemical_element Condensed Matter Physics Acceptor Surfaces Coatings and Films Electronic Optical and Magnetic Materials Depletion region chemistry Materials Chemistry Electrical and Electronic Engineering Platinum Instrumentation Layer (electronics) Surface states |
| Zdroj: | Sensors and Actuators B: Chemical. 47:213-217 |
| ISSN: | 0925-4005 |
| Popis: | The conductance of a thin SnO 2 film in contact with platinum is used to detect NO 2 down to the 10 ppb range with a cross sensitivity to CO of the order of only 10 −4 . The SnO 2 layer thickness of 60 nm is chosen of the order of the depletion layer caused by the action of adsorbed oxygen ions and by the Schottky contact at the platinum interface. By a strong sintering pretreatment potential barriers between the grains are avoided and a diffusion of the ambient gas into the layer is suppressed. The width of the conductive channel in the middle of the SnO 2 layer is reduced in the presence of NO 2 adsorbed on the surface. This strongly electrophilic molecule forms acceptor surface states energetically below the acceptor states of the adsorbed oxygen thus enhancing the electron depletion. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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