Impedance Spectroscopy of Encapsulated Single Graphene Layers

In this work, we demonstrate the use of electrical impedance spectroscopy (EIS) for the disentanglement of several dielectric contributions in encapsulated single graphene layers. The dielectric data strongly vary qualitatively with the nominal graphene resistance. In the case of sufficiently low resistance of the graphene layers, the dielectric spectra are dominated by inductive contributions, which allow for disentanglement of the electrode/graphene interface resistance from the intrinsic graphene resistance by the application of an adequate equivalent circuit model. Higher resistance of the graphene layers leads to predominantly capacitive dielectric contributions, and the deconvolution is not feasible due to the experimental high frequency limit of the EIS technique.

Automated summary

This work demonstrates the use of electrical impedance spectroscopy (EIS) to analyze the dielectric contributions in encapsulated single graphene layers. The dielectric data qualitatively vary with the resistance of the graphene layers. For low graphene resistance, the dielectric spectra are dominated by inductive contributions, which can be separated from the intrinsic graphene resistance using an appropriate equivalent circuit model. However, for high graphene resistance, the analysis is not feasible due to the limitations of the EIS technique at high frequencies.