ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
By combining the advantages of a catalytic palladium (Pd thin film) with ahigh-performance GaAs-based transistor, an interesting hydrogen sensor is fabricated anddemonstrated. For the studied device, a 50 Å undoped GaAs cap layer is grown to prevent theAl0.24Ga0.76As Schottky layer from oxidizing and to suppress the Fermi level pinning effect. Thesensing mechanism can be described as the dissociation of hydrogen molecules and the polarizationof hydrogen atoms. The drain-source variation ΔIDS is caused by the polarization of a dipolar layerresulting in the modulation of the gate potential and carrier density level. Experimentally, a highhydrogen detection sensitivity SJ value of 275.8 mA/mm-ppm H2/air can be obtained under the14ppm H2/air gas. Even under a very low hydrogen concentration (≤4.3 ppm H2/air) at 303K, theconsiderable current variation can be observed. Moreover, the fast hydrogen response is found.Therefore, the studied device reveals the promise for high-performance hydrogen sensorapplications
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.15-17.275.pdf
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