Unraveling the origin of local variations in the step resistance of epitaxial graphene on SiC

a quantitative scanning tunneling potentiometry study

authored by: Anna Sinterhauf, Georg A. Traeger, Davood Momeni, Klaus Pierz, Hans Werner Schumacher, Martin Wenderoth
Abstract: By combining highly resolved Scanning Tunneling Potentiometry with the exceptional sample homogeneity of graphene on SiC epitaxially grown by polymer-assisted sublimation growth, we reveal local variations in the resistance associated with substrate steps. We quantify these variations and show that they are an intrinsic property of graphene on SiC. Furthermore, we trace back their origin to variations in the electronic structure of the interface and, thereby, demonstrate the crucial impact of intrinsic proximity effects in graphene on SiC. Moreover, we find a correlation of the step resistance with the local conductivity and show that at room temperature, the step resistance decreases with increasing local conductivity, whereas at low temperatures, it increases with increasing local conductivity. We attribute this inversion to an interplay between the reduction in electron-phonon scattering and potential scattering with decreasing temperature, and the efficiency of the built-up of an almost completely charge carrier depleted zone at the position of the substrate step.
External Organisation(s): University of Göttingen
National Metrology Institute of Germany (PTB)
Type: Article
Journal: CARBON
Volume: 184
Pages: 463-469
No. of pages: 7
ISSN: 0008-6223
Publication date: 30.10.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Chemistry(all), Materials Science(all)
Electronic version(s): https://doi.org/10.1016/j.carbon.2021.08.050 (Access: Open)

BibTeX

@article{875ce5fc644549ecbda8c53b32cf1553,
title = "Unraveling the origin of local variations in the step resistance of epitaxial graphene on SiC: a quantitative scanning tunneling potentiometry study",
abstract = "By combining highly resolved Scanning Tunneling Potentiometry with the exceptional sample homogeneity of graphene on SiC epitaxially grown by polymer-assisted sublimation growth, we reveal local variations in the resistance associated with substrate steps. We quantify these variations and show that they are an intrinsic property of graphene on SiC. Furthermore, we trace back their origin to variations in the electronic structure of the interface and, thereby, demonstrate the crucial impact of intrinsic proximity effects in graphene on SiC. Moreover, we find a correlation of the step resistance with the local conductivity and show that at room temperature, the step resistance decreases with increasing local conductivity, whereas at low temperatures, it increases with increasing local conductivity. We attribute this inversion to an interplay between the reduction in electron-phonon scattering and potential scattering with decreasing temperature, and the efficiency of the built-up of an almost completely charge carrier depleted zone at the position of the substrate step.",
keywords = "Charge carrier depletion, Epitaxial graphene/SiC, Local-scale charge transport, Localized defects, Scanning tunneling potentiometry, Substrate steps",
author = "Anna Sinterhauf and Traeger, {Georg A.} and Davood Momeni and Klaus Pierz and Schumacher, {Hans Werner} and Martin Wenderoth",
note = "Funding information: Financial support of the Deutsche Forschungsgemeinschaft (DFG) through project We 1889/13–1 is gratefully acknowledged. The preparation of the samples was funded by the Deutsche Forschungsgemeinschaft (DFG) under Germany's Excellence Strategy - EXC-2123 QuantumFrontiers - 390837967 .",
year = "2021",
month = oct,
day = "30",
doi = "10.1016/j.carbon.2021.08.050",
language = "English",
volume = "184",
pages = "463--469",
journal = "CARBON",
issn = "0008-6223",
publisher = "Elsevier Ltd.",
}