We detect changes in the optical properties of a metal oxide semiconductor (MOS), ZnO, in a multi-thin-film matrix with platinum in the presence of the hydrocarbon gas methane. A limit of detection of 2% by volume with concentrations from 0 to 10% and maximum resolution of 0.15% with concentrations ranging from 30% to 80% at room temperature are demonstrated along with a selective chemical response to methane over carbon dioxide and the other alkane gases. The device yields the equivalent maximum bulk refractive index spectral sensitivity of 1.8 × 105 nm/RIU. This is the first time that the optical properties of MOS have been monitored to detect the presence of a specific gas. This single observation is a significant result, as MOS have a potentially large number of target gases, thus offering a new paradigm for gas sensing using MOSs.
Bibliographical note© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Funding: Grants EP/J010413 and EP/J010391 for Aston University and University of Plymouth from the UK Engineering and Physical Sciences Research Council.
- localized surface plasmons
- metal oxide semiconductors
- optical sensing
- gas sensing
- fibre optics
Allsop, T., Kundrat, V., Kalli, K., Lee, G. B., Neal, R., Bond, P., Shi, B., Sullivan, J., Culverhouse, P., & Webb, D. J. (2018). Methane detection scheme based upon the changing optical constants of a zinc oxide/platinum matrix created by a redox reaction and their effect upon surface plasmons. Sensors and Actuators, B: Chemical, 255(1), 843-853. https://doi.org/10.1016/j.snb.2017.08.058