GS3.2 - Temperature-Modulated pn-Transition Gas Response of ZnO Nanorod Arrays for Selective Detection of CO
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- Gas Sensors 3
- 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)
- 128 - 129
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.