Performance tuning of gas sensors based on epitaxial graphene on silicon carbide

Publication date: 5 September 2018
Source:Materials & Design, Volume 153
Author(s): Marius Rodner, Jasna Bahonjic, Marcus Mathisen, Rickard Gunnarsson, Sebastian Ekeroth, Ulf Helmersson, Ivan G. Ivanov, Rositsa Yakimova, Jens Eriksson
In this study, we investigated means of performance enhancement in sensors based on epitaxial graphene on silicon carbide (SiC). Epitaxially grown graphene on SiC substrates were successfully decorated with metal oxide nanoparticles such as TiO2 and Fe3O4 using hollow cathode pulsed plasma sputtering. Atomic Force Microscopy and Raman data verified that no damage was added to the graphene surface. It could be shown that it was easily possible to detect benzene, which is one of the most dangerous volatile organic compounds, with the Fe3O4 decorated graphene sensor down to an ultra-low concentration of 5 ppb with a signal to noise ratio of 35 dB. Moreover, upon illumination with a UV light LED (265 nm) of the TiO2 decorated graphene sensor, the sensitivity towards a change of oxygen could be enhanced such that a clear sensor response could be seen which is a significant improvement over dark conditions, where almost no response occurred. As the last enhancement, the time derivative sensor signal was introduced for the sensor data evaluation, testing the response towards a change of oxygen. This sensor signal evaluation approach can be used to decrease the response time of the sensor by at least one order of magnitude.

Graphical abstract

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