Building a cm2scale CVD graphene-based gas sensor: modelling the kinetic with a three-site adsorption/desorption Langmuir model

Abstract

In this article, we aim to develop and study a highly sensitive and selective cm²scale graphene-based gas sensor. We present the technology used to fabricate sensors which integrate monolayer chemical vapour deposition graphene: photolithography and transfer of layers. Characterization techniques (optical microscopy, AFM, micro-Raman spectroscopy, transport electrical measurements) ensure a diagnosis of graphene ribbons and allow good reproducibility of technological processes. We present the results of gas characterizations after a 200 ppm NO₂exposure. We propose a novel approach for the modelling of the sensor response with a three-site adsorption/desorption Langmuir model. This innovative way of modelling the sensor response should provide a better understanding of the sensor's kinetic and help to overcome the long response time observed with graphene gas sensors.

Keywords: Langmuir model; cm2 scale graphene devices; gas detection; graphene characterization; graphene sensor.