Article ID Journal Published Year Pages File Type
747405 Sensors and Actuators B: Chemical 2006 7 Pages PDF
Abstract

Single-walled carbon nanotube (CNT) gas sensors were fabricated by dielectrophoresis onto microelectrodes made of Cr, Pd or Al. The Al/CNT sensor response to NO2 (nitrogen dioxide) gas was characterized by fast and large resistance increase at the moment of NO2 exposure, whereas the resistance of the other metal/CNT sensors monotonously decreased. It was suggested that the adsorbed NO2 molecules might alter the Schottky barrier at the Al/CNT interface as well as the positive hole density in the p-type semiconducting CNT. The Al/CNT sensor response could be interpreted as a superposition of the Schottky contact resistance and the CNT resistance, which were differently influenced by the NO2 adsorption and contributed to the overall sensor response. The Schottky response of the Al/CNT sensor was approximately one order of magnitude faster than the CNT response obtained using the other metal electrodes.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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