New IEC standards for the measurement of sheet resistance on large-area graphene using the van der Pauw and the in-line four-point probe methods

Graphene has evolved from a scientific research subject to an industrial product, in need of a normative basis for its key control characteristics. Recently two new IEC technical specifications that establish standardized procedures for assessing the sheet resistance RSof monolayer graphene have been published. These new standards, part of the IEC TS 62607-6-xx series, outline protocols for employing two contact methods: i) van der Pauw, and ii) in-line four-point probe. In the following we present and discuss illustrative examples of the scientific experiments designed and performed to inform the standardization process behind the presented standards. In particular we report about the investigation of mechanical contacting of chemical-vapor-deposited monolayer graphene and the measurement of the RSin cm2 area graphene samples with non uniform resistivity distributions. This paper includes an overview of the broader IEC context, detailing the key steps in the development of the standards themselves.