Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

A patterning-free approach for growth of free-standing graphene nanoribbons using step-bunched facets of off-oriented 4H-SiC(0 0 0 1) epilayers

Shi, Yuchen ; Zakharov, Alexei A. LU ; Ivanov, Ivan G. ; Vinogradov, Nikolay A. LU orcid ; Yazdi, G. Reza ; Syväjärvi, Mikael ; Yakimova, Rositsa and Sun, Jianwu (2020) In Journal of Physics D: Applied Physics 53(11).
Abstract

The tunable electronic structure of graphene nanoribbons (GNRs) has attracted much attention due to the great potential in nanoscale electronic applications. Most methods to produce GNRs rely on the lithographic process, which suffers from the process-induced disorder in the graphene and scalability issues. Here, we demonstrate a novel approach to directly grow free-standing GNRs on step-bunched facets of off-oriented 4H-SiC epilayers without any patterning or lithography. First, the 4H-SiC epilayers with well-defined bunched steps were intentionally grown on 4 degree off-axis 4H-SiC substrates by the sublimation epitaxy technique. As a result, periodic step facets in-between SiC terraces were obtained. Then, graphene layers were grown... (More)

The tunable electronic structure of graphene nanoribbons (GNRs) has attracted much attention due to the great potential in nanoscale electronic applications. Most methods to produce GNRs rely on the lithographic process, which suffers from the process-induced disorder in the graphene and scalability issues. Here, we demonstrate a novel approach to directly grow free-standing GNRs on step-bunched facets of off-oriented 4H-SiC epilayers without any patterning or lithography. First, the 4H-SiC epilayers with well-defined bunched steps were intentionally grown on 4 degree off-axis 4H-SiC substrates by the sublimation epitaxy technique. As a result, periodic step facets in-between SiC terraces were obtained. Then, graphene layers were grown on such step-structured 4H-SiC epilayers by thermal decomposition of SiC. Scanning tunneling microscopy (STM) studies reveal that the inclined step facets are about 13-15 nm high and 30-35 nm wide, which gives an incline angle of 23-25 degrees. LEEM and LEED results showed that the terraces are mainly covered by monolayer graphene and the buffer layer underneath it. STM images and the analysis of their Fourier transform patterns suggest that on the facets, in-between terraces, graphene is strongly buckled and appears to be largely decoupled from the surface.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
4H-SiC homoepilayer, Free-standing graphene nanoribbons, Patterning-free, Step-bunched facets, Sublimation epitaxy
in
Journal of Physics D: Applied Physics
volume
53
issue
11
article number
115102
publisher
IOP Publishing
external identifiers
  • scopus:85079546135
ISSN
0022-3727
DOI
10.1088/1361-6463/ab6149
language
English
LU publication?
yes
id
08e6328c-d274-4054-9970-087b9b774e9c
date added to LUP
2021-01-13 00:37:31
date last changed
2022-04-19 03:38:31
@article{08e6328c-d274-4054-9970-087b9b774e9c,
  abstract     = {{<p>The tunable electronic structure of graphene nanoribbons (GNRs) has attracted much attention due to the great potential in nanoscale electronic applications. Most methods to produce GNRs rely on the lithographic process, which suffers from the process-induced disorder in the graphene and scalability issues. Here, we demonstrate a novel approach to directly grow free-standing GNRs on step-bunched facets of off-oriented 4H-SiC epilayers without any patterning or lithography. First, the 4H-SiC epilayers with well-defined bunched steps were intentionally grown on 4 degree off-axis 4H-SiC substrates by the sublimation epitaxy technique. As a result, periodic step facets in-between SiC terraces were obtained. Then, graphene layers were grown on such step-structured 4H-SiC epilayers by thermal decomposition of SiC. Scanning tunneling microscopy (STM) studies reveal that the inclined step facets are about 13-15 nm high and 30-35 nm wide, which gives an incline angle of 23-25 degrees. LEEM and LEED results showed that the terraces are mainly covered by monolayer graphene and the buffer layer underneath it. STM images and the analysis of their Fourier transform patterns suggest that on the facets, in-between terraces, graphene is strongly buckled and appears to be largely decoupled from the surface.</p>}},
  author       = {{Shi, Yuchen and Zakharov, Alexei A. and Ivanov, Ivan G. and Vinogradov, Nikolay A. and Yazdi, G. Reza and Syväjärvi, Mikael and Yakimova, Rositsa and Sun, Jianwu}},
  issn         = {{0022-3727}},
  keywords     = {{4H-SiC homoepilayer; Free-standing graphene nanoribbons; Patterning-free; Step-bunched facets; Sublimation epitaxy}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{11}},
  publisher    = {{IOP Publishing}},
  series       = {{Journal of Physics D: Applied Physics}},
  title        = {{A patterning-free approach for growth of free-standing graphene nanoribbons using step-bunched facets of off-oriented 4H-SiC(0 0 0 1) epilayers}},
  url          = {{http://dx.doi.org/10.1088/1361-6463/ab6149}},
  doi          = {{10.1088/1361-6463/ab6149}},
  volume       = {{53}},
  year         = {{2020}},
}