Room-temperature semiconductor gas sensor based on nonstoichiometric tungsten oxide nanorod film

Yong Shin Kim, Seung Chul Ha, Kyuwon Kim, Haesik Yang, Sung Yool Choi, Youn Tae Kim, Joon T. Park, Chang Hoon Lee, Jiyoung Choi, Jungsun Paek, Kwangyeol Lee

Research output: Contribution to journalArticlepeer-review

249 Citations (Scopus)


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 languageEnglish
Article number213105
Pages (from-to)1-3
Number of pages3
JournalApplied Physics Letters
Issue number21
Publication statusPublished - 2005 May 23

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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