Reproducibility of the performances of graphene-based gas-sensitive chemiresistors

The potential of graphene as sensing layer relies on its two-dimensional nature that provides the greatest sensor area per unit volume. Thanks to this property, besides the highest mobility and the lowest resistivity values, graphene has put itself as the leader of the new discovered materials in every research field. Graphene can be produced by various approaches including micromechanical exfoliation of graphite, thermal dissociation of SiC, chemical vapor deposition, or by low-cost approaches such as chemical exfoliation methods. However, the sensor device development is still affected by several technological limitations mainly related to graphene preparation, introduction into device architectures, and reproducibility of the sensor performances. Regarding the last item, sensing performance may differ from device to device even though graphene materials come from the same batch and the same fabrication protocol. In this work, chemiresistive devices based on chemically exfoliated natural graphite are presented. Several parameters were taken into account: graphene preparation (including solvents, centrifugation speed, and batch), deposition, and conductance. Finally the device-to-device variation is addressed. © 2014 Springer International Publishing Switzerland.