Comparative study on micromorphology and humidity sensitive properties of thin-film and thick-film humidity sensors based on semiconducting MnWO4
| Autor: | Wojtek Wlodarski, Jörg-Uwe Meyer, Wenmin Qu |
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| Rok vydání: | 2000 |
| Předmět: |
Materials science
Capillary action Metals and Alloys Humidity Nanotechnology Electrolyte Atmospheric temperature range Condensed Matter Physics Thermal conduction Surfaces Coatings and Films Electronic Optical and Magnetic Materials Adsorption Materials Chemistry Electrical and Electronic Engineering Thin film Composite material Instrumentation Temperature coefficient |
| Zdroj: | Sensors and Actuators B: Chemical. 64:76-82 |
| ISSN: | 0925-4005 |
| Popis: | Based on our experience of developing thick-film MnWO4 humidity sensors, a thin-film humidity sensor with nano-sized MnWO4 grains has been fabricated using the sol–gel technique. The thin-film sensor shows smaller humidity sensitivity than that compared to a thick-film sensor. However, it exhibits a fast response to humidity change and also has a very low temperature coefficient within the temperature range of 20–60°C. The absence of capillary pores in the well defined thin-films makes water condensation, and hence electrolytic conduction, impossible. The physically adsorbed multi-layered water molecules on the surface of the thin sensing film play a dominating role for the humidity sensing mechanism. Studies on thin-film sensors based on MnO and WO3 indicate that the W+6 sites in the hubnerite material contribute strongly to the humidity sensing mechanism. |
| Databáze: | OpenAIRE |
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