Abstract
Porous tungsten oxide films were deposited onto a sensor substrate with a Si bulk-micromachined hotplate, by drop-coating isopropyl alcohol solution of highly crystalline tungsten oxide (W O2.72) nanorods with average 75 nm length and 4 nm diameter. The temperature-dependent gas sensing characteristics of the films have been investigated over the mild temperature range from 20 to 250 °C. While the sensing responses for ammonia vapor showed increase in electrical conductivity at temperatures above 150 °C as expected for n -type metal oxide sensors, they exhibited the opposite behavior of unusual conductivity decrease below 100 °C. Superb sensing ability of the sensors at room temperature in conjunction with their anomalous conductivity behavior might be attributed to unique nanostructural features of very thin, nonstoichiometric W O2.72.
Original language | English |
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Article number | 213105 |
Pages (from-to) | 1-3 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 86 |
Issue number | 21 |
DOIs | |
Publication status | Published - 2005 May 23 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)