GS3.2 - Temperature-Modulated pn-Transition Gas Response of ZnO Nanorod Arrays for Selective Detection of CO

Event
17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
Chapter
Gas Sensors 3
Author(s)
T. Yang, W. Jin, W. Chen - State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan (China)
Pages
128 - 129
DOI
10.5162/IMCS2018/GS3.2
ISBN
978-3-9816876-9-9
Price
free

Abstract

It has been problematic to selectively detect CO by metal oxide semiconductor (MOS) gas sensors, due to gas response to CO is normally much lower than volatile organic compounds (VOCs). In this work, an abnormal pn-transition gas response of ZnO nanorod arrays is discovered. At relatively low temperature (463 K), resistance of ZnO nanorod arrays increases when CO is injected into testing chamber, suggesting a "p-type" gas response; while, at relatively high temperature (643 K), resistance decreases after CO injection, meaning a usual "n-type" response. Density functional theory (DFT) simulation reveals that the abnormal p-type response at 463 K is attributed to CO molecule facilitating the dissociation of absorbed O2 molecule. This peculiarity can be applied to selective detection of CO.

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