title: Hierarchy of electronic properties of chemically derived and pristine graphene probed by microwave imaging.
abstract: Local electrical imaging using microwave impedance microscope is performed on graphene in different modalities, yielding a rich hierarchy of the local conductivity. The low-conductivity graphite oxide and its derivatives show significant electronic inhomogeneity. For the conductive chemical graphene, the residual defects lead to a systematic reduction of the microwave signals. In contrast, the signals on pristine graphene agree well with a lumped-element circuit model. The local impedance information can also be used to verify the electrical contact between overlapped graphene pieces.
authors.affiliation: Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305,USA.
authors.forename: Worasom
authors.initials: W
authors.lastname: Kundhikanjana
authors.forename: Keji
authors.initials: K
authors.lastname: Lai
authors.forename: Hailiang
authors.initials: H
authors.lastname: Wang
authors.forename: Hongjie
authors.initials: H
authors.lastname: Dai
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kelly
authors.forename: Zhi-Xun
authors.initials: ZX
authors.lastname: Shen