Unveiling conducting pathways embedded in strongly disordered graphene

Graphene shows very different electrical properties under the influence of electrical environments. For example, pristine graphene can show either insulating or normally metallic behavior when supported by different substrates. Here we study charge transport in disordered graphene grown by chemical vapor deposition with varying channel widths. We demonstrate that at high temperatures homogeneous hopping governs the electrical characteristics, whereas at low enough temperatures where charge hopping is frozen out carriers through the embedded weakly disordered conducting pathways contribute a finite conductance instead of being strongly insulating. Our work not only reveals their inhomogeneous features but also provides a new approach for characterizing the surface disorder in large-area graphene systems.