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Effect of Substrate Chemistry on the Bottom-Up Fabrication of Graphene Nanoribbons: Combined Core-Level Spectroscopy and STM Study

Simonov, Konstantin LU ; Vinogradov, Nikolay LU ; Vinogradov, Alexander S.; Generalov, Alexander LU ; Zagrebina, Elena M.; Martensson, Nils; Cafolla, Attilio A.; Carpy, Tomas; Cunniffe, John P. and Preobrajenski, Alexei LU (2014) In Journal of Physical Chemistry C 118(23). p.12532-12540
Abstract
Atomically precise graphene nanoribbons (GNRs) can be fabricated via thermally induced polymerization of halogen containing molecular precursors on metal surfaces. In this paper the effect of substrate reactivity on the growth and structure of armchair GNRs (AGNRs) grown on inert Au(111) and active Cu(111) surfaces has been systematically studied by a combination of core-level X-ray spectroscopies and scanning tunneling microscopy. It is demonstrated that the activation threshold for the dehalogenation process decreases with increasing catalytic activity of the substrate. At room temperature the 10,10'-dibromo-9,9'-bianthracene (DBBA) precursor molecules on Au(111) remain intact, while on Cu(111) a complete surface-assisted dehalogenation... (More)
Atomically precise graphene nanoribbons (GNRs) can be fabricated via thermally induced polymerization of halogen containing molecular precursors on metal surfaces. In this paper the effect of substrate reactivity on the growth and structure of armchair GNRs (AGNRs) grown on inert Au(111) and active Cu(111) surfaces has been systematically studied by a combination of core-level X-ray spectroscopies and scanning tunneling microscopy. It is demonstrated that the activation threshold for the dehalogenation process decreases with increasing catalytic activity of the substrate. At room temperature the 10,10'-dibromo-9,9'-bianthracene (DBBA) precursor molecules on Au(111) remain intact, while on Cu(111) a complete surface-assisted dehalogenation takes place. Dehalogenation of precursor molecules on Au(111) only starts at around 80 degrees C and completes at 200 degrees C, leading to the formation of linear polymer chains. On Cu(111) tilted polymer chains appear readily at room temperature or slightly elevated temperatures. Annealing of the DBBA/Cu(111) above 100 degrees C leads to intramolecular cyclodehydrogenation and formation of flat AGNRs at 200 degrees C, while on the Au(111) surface the formation of GNRs takes place only at around 400 degrees C. In STM, nanoribbons have significantly reduced apparent height on Cu(111) as compared to Au(111), 70 +/- 11 pm versus 172 +/- 14 pm, independently of the bias voltage. Moreover, an alignment of GNRs along low-index crystallographic directions of the substrate is evident for Cu(111), while on Au(111) it is more random. Elevating the Cu(111) substrate temperature above 400 degrees C results in a dehydrogenation and subsequent decomposition of GNRs; at 750 degrees C the dehydrogenated carbon species self-organize in graphene islands. In general, our data provide evidence for a significant influence of substrate reactivity on the growth dynamics of GNRs. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry C
volume
118
issue
23
pages
12532 - 12540
publisher
The American Chemical Society
external identifiers
  • wos:000337497400051
  • scopus:84902440316
ISSN
1932-7447
DOI
10.1021/jp502215m
language
English
LU publication?
yes
id
2286058b-5a1d-442e-9268-7ea5378a10a7 (old id 4609577)
date added to LUP
2014-08-25 16:10:48
date last changed
2017-11-19 03:08:33
@article{2286058b-5a1d-442e-9268-7ea5378a10a7,
  abstract     = {Atomically precise graphene nanoribbons (GNRs) can be fabricated via thermally induced polymerization of halogen containing molecular precursors on metal surfaces. In this paper the effect of substrate reactivity on the growth and structure of armchair GNRs (AGNRs) grown on inert Au(111) and active Cu(111) surfaces has been systematically studied by a combination of core-level X-ray spectroscopies and scanning tunneling microscopy. It is demonstrated that the activation threshold for the dehalogenation process decreases with increasing catalytic activity of the substrate. At room temperature the 10,10'-dibromo-9,9'-bianthracene (DBBA) precursor molecules on Au(111) remain intact, while on Cu(111) a complete surface-assisted dehalogenation takes place. Dehalogenation of precursor molecules on Au(111) only starts at around 80 degrees C and completes at 200 degrees C, leading to the formation of linear polymer chains. On Cu(111) tilted polymer chains appear readily at room temperature or slightly elevated temperatures. Annealing of the DBBA/Cu(111) above 100 degrees C leads to intramolecular cyclodehydrogenation and formation of flat AGNRs at 200 degrees C, while on the Au(111) surface the formation of GNRs takes place only at around 400 degrees C. In STM, nanoribbons have significantly reduced apparent height on Cu(111) as compared to Au(111), 70 +/- 11 pm versus 172 +/- 14 pm, independently of the bias voltage. Moreover, an alignment of GNRs along low-index crystallographic directions of the substrate is evident for Cu(111), while on Au(111) it is more random. Elevating the Cu(111) substrate temperature above 400 degrees C results in a dehydrogenation and subsequent decomposition of GNRs; at 750 degrees C the dehydrogenated carbon species self-organize in graphene islands. In general, our data provide evidence for a significant influence of substrate reactivity on the growth dynamics of GNRs.},
  author       = {Simonov, Konstantin and Vinogradov, Nikolay and Vinogradov, Alexander S. and Generalov, Alexander and Zagrebina, Elena M. and Martensson, Nils and Cafolla, Attilio A. and Carpy, Tomas and Cunniffe, John P. and Preobrajenski, Alexei},
  issn         = {1932-7447},
  language     = {eng},
  number       = {23},
  pages        = {12532--12540},
  publisher    = {The American Chemical Society},
  series       = {Journal of Physical Chemistry C},
  title        = {Effect of Substrate Chemistry on the Bottom-Up Fabrication of Graphene Nanoribbons: Combined Core-Level Spectroscopy and STM Study},
  url          = {http://dx.doi.org/10.1021/jp502215m},
  volume       = {118},
  year         = {2014},
}