The Parameter Space of Graphene CVD on Polycrystalline Cu
Authors
Kidambi, Piran
Dlubak, Bruno
Gardiner, Damian
Martin, Marie-Blandine
Seneor, Pierre
Coles, Harry
Publication Date
2012-09-27Journal Title
Journal of Physical Chemistry C
ISSN
1932-7447
Publisher
American Chemical Society
Volume
116
Pages
22492-22501
Language
English
Type
Article
Metadata
Show full item recordCitation
Kidambi, P., Ducati, C., Dlubak, B., Gardiner, D., Weatherup, R., Martin, M., Seneor, P., et al. (2012). The Parameter Space of Graphene CVD on Polycrystalline Cu. Journal of Physical Chemistry C, 116 22492-22501. https://doi.org/10.1021/jp303597m
Abstract
A systematic study on the parameter space of graphene CVD on polycrystalline Cu foils is
presented, aiming at a more fundamental process rationale in particular regarding the choice
of carbon precursor and mitigation of Cu sublimation. CH4 as precursor requires H2 dilution
and temperatures ≥1000°C to keep the Cu surface reduced and yield a high quality, complete
monolayer graphene coverage. The H2 atmosphere etches as-grown graphene, hence
maintaining a balanced CH4/H2 ratio is critical. Such balance is more easily achieved at low
pressure conditions, at which however Cu sublimation reaches deleterious levels. In contrast,
C6H6 as precursor requires no reactive diluent and consistently gives similar graphene quality
at 100-150°C lower temperatures. The lower process temperature and more robust processing
conditions allow the problem of Cu sublimation to be effectively addressed. Graphene
formation is not inherently self-limited to a monolayer for any of the precursors. Rather, the
higher the supplied carbon chemical potential the higher the likelihood of film inhomogeneity
and primary and secondary multilayer graphene nucleation. For the latter, domain boundaries
of the inherently polycrystalline CVD graphene offer pathways for a continued carbon supply
to the catalyst. Graphene formation is significantly affected by the Cu crystallography, i.e. the
evolution of microstructure and texture of the catalyst template form an integral part of the
CVD process.
Keywords
mono and few-layer graphene (M/FLG), chemical vapor deposition (CVD), copper (Cu), polycrystalline, methane (CH4), benzene (C6H6)
Sponsorship
S.H. acknowledges funding from ERC grant InsituNANO (n°279342) and from EPSRC
(Grant Nr. EP/H047565/1). P.R.K. acknowledges funding from the Cambridge
Commonwealth Trust and C.D. acknowledges funding from Royal Society.
Funder references
EPSRC (EP/H047565/1)
Identifiers
External DOI: https://doi.org/10.1021/jp303597m
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246856
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