Charge‐Carrier Transport in Large‐Area Epitaxial Graphene

Abstract

We present an overview of recent charge carrier transport experiments in both monolayer and bilayer graphene, with emphasis on the phenomena that appear in large-area samples. While many aspects of transport are based on quantum mechanical concepts, in the large-area limit classical corrections dominate and shape the magnetoresistance and the tunneling conductance. The discussed phenomena are very general and can, with little modification, be expected in any atomically thin 2D conductor.

Fractional Quantum Conductance Plateaus in Mosaic‐Like Conductors and Their Similarities to the Fractional Quantum Hall Effect

“…Partial dislocations are extended line defects which thread the 2D plane. They invoke a quantum mechanical separation of electronic states on both sides of the partial dislocations which can be expressed by orthogonality of eigenstates in AB and AC areas close to charge neutrality. Other groups have chosen a description in terms of topological properties of the domains, and topological edge states that run along the partial dislocation lines .…”

“…Recent studies elucidated how stacking faults can drastically alter the electronic properties of bilayer graphene . In particular, partial dislocations split the area into a mosaic consisting of two types of regions which exhibit quantum mechanically orthogonal wavefunctions . This decomposition is not limited to atomically thin materials: for embedded 2D semiconductor heterostructures, substrate steps or stacking faults in the surrounding crystal can create such extended defects.…”

Fractional Quantum Hall plateaus in mosaic-like conductors

“…Partial dislocations are extended line defects which thread the 2D plane. They invoke a quantum mechanical separation of electronic states on both sides of the partial dislocations which can be expressed by orthogonality of eigenstates in AB and AC areas [20,21] close to charge neutrality. Other groups have chosen a description in terms of topological properties of the domains, and topological edge states that run along the partial dislocation lines [17,19].…”

“…Recent studies elucidated how stacking faults can drastically alter the electronic properties of bilayer graphene [14,15,16,17,18,19]. In particular, partial dislocations split the area into a mosaic consisting of two types of regions which exhibit quantum mechanically orthogonal wavefunctions [20,21]. This decomposition is not limited to atomically thin materials: for embedded 2D semiconductor heterostructures, substrate steps or stacking faults in the surrounding crystal can create such extended defects.…”

Contactless millimeter wave method for quality assessment of large area graphene

“…Whereas fundamental physical investigations of the integer and fractional quantum hall effect [2,3], of Klein tunneling [4] or of semi-metallicity in graphene [5] can be carried out on micrometer scale devices there is a demand for large area, uniform, high quality, reproducible and cost-effective graphene [6] for a wide range of applications, as for instance electrodes [7], field-effect transistors [8], membranes [9], optoelectronics [10], solar cells [11] or optical modulators [12]. Furthermore, in smaller sized samples, the low energy properties of the charge carriers are suppressed [13]. While in graphene samples that are naturally grown on graphite, mobilities can exceed 1 × 10 6 cm 2 V −1 s −1 [14] the mobility of man-made 'gently' hydrogen intercalated graphene synthesized on SiC is in the range of 1 × 10 4 cm 2 V −1 s −1 for samples <1 mm 2 [15,16].…”