Thermoelectric imaging of structural disorder in epitaxial graphene

Abstract

Heat is a familiar form of energy transported from a hot side to a colder side of an object, but not a notion associated with microscopic measurements of electronic properties. A temperature difference within a material causes charge carriers, electrons or holes, to diffuse along the temperature gradient inducing a thermoelectric voltage. Here we show that local thermoelectric measurements can yield high sensitivity imaging of structural disorder on the atomic and nanometre scales. The thermopower measurement acts to amplify the variations in the local density of states at the Fermi-level, giving high differential contrast in thermoelectric signals. Using this imaging technique, we uncovered point defects in the first layer of epitaxial graphene, which generate soliton-like domain wall line patterns separating regions of the different interlayer stacking of the second graphene layer.

Main Text (19 pages including 5 figures) + Supplementary Information (6 pages including 10 figures, simplified version)

References in corpus (6)

• Substrate-induced band gap opening in epitaxial graphene
• Topological Defects in Graphene: Dislocations and Grain Boundaries
• Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
• Strain Solitons and Topological Defects in Bilayer Graphene
• Evidence of structural strain in epitaxial graphene layers on 6H-SiC(0001)
• Imaging the interface of epitaxial graphene with silicon carbide via scanning tunneling microscopy

Cited by in corpus (14)

• Strain Solitons and Topological Defects in Bilayer Graphene
• Thermal and Thermoelectric Properties of Graphene
• Near-field photocurrent nanoscopy on bare and encapsulated graphene
• Competing Channels for Hot Electron Cooling in Graphene
• Maximizing the thermoelectric performance of topological insulator Bi2Te3 films in the few-quintuple layer regime
• Direct electronic measurement of Peltier cooling and heating in graphene
• Unified picture for the colossal thermopower compound FeSb${}_2$
• Derivation of a governing rule in triboelectric charging and series from thermoelectricity
• Seebeck effect at the atomic scale
• Controlling the thermoelectric effect by mechanical manipulation of the electron's quantum phase in atomic junctions
• Stacking domain morphology in epitaxial graphene on silicon carbide
• Effect of C-face 4H-SiC(0001) deposition on thermopower of single and multilayer graphene in AA, AB and ABC stacking
• Anomalous thermopower oscillations in graphene-InAs nanowire vertical heterostructures
• Importance of Schottky barriers for wide-bandgap thermoelectric devices