Impact of the in situ rise in hydrogen partial pressure on graphene shape evolution during CVD growth of graphene
Gebeyehu, Zewdu M. (Institut Català de Nanociència i Nanotecnologia)
Costache, Marius Vasile. (Institut Català de Nanociència i Nanotecnologia)
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)
Esplandiu Egido, Maria José (Institut Català de Nanociència i Nanotecnologia)
Valenzuela, Sergio O. (Institut Català de Nanociència i Nanotecnologia)
Arrighi, Aloïs (Institut Català de Nanociència i Nanotecnologia)

Date:	2018
Abstract:	Growth to etching transformation following in situ rise in hydrogen with time results in dendritic graphene. Exposing graphene to a hydrogen post-etching process yields dendritic graphene shapes. Here, we demonstrate that similar dendritic structures can be achieved at long growth times without adding hydrogen externally. These shapes are not a result of a surface diffusion controlled growth but of the competing backward reaction (etching), which dominates the growth dynamics at long times due to an in situ rise in the hydrogen partial pressure. We have performed a systematic study on the growth of graphene as a function of time to identify the onset and gradual evolution of graphene shapes caused by etching and then demonstrated that the etching can be stopped by reducing the flow of hydrogen from the feed. In addition, we have found that the etching rate due to the in situ rise in hydrogen is strongly dependent on the confinement (geometrical confinement) of copper foil. Highly etched graphene with dendritic shapes was observed in unconfined copper foil regions while no etching was found in graphene grown in a confined reaction region. This highlights the effect of the dynamic reactant distribution in activating the in situ etching process during growth, which needs to be counteracted or controlled for large scale growth.
Grants:	European Commission 696656 European Commission 306652 Ministerio de Economía y Competitividad MAT2016-75952-R Ministerio de Economía y Competitividad BES-2014-069925 Ministerio de Economía y Competitividad MAT2015-68307-P Ministerio de Economía y Competitividad MAT2013-46785-P Ministerio de Economía y Competitividad SEV-2013-0295
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	RSC advances, Vol. 8, issue 15 (2018) , p. 8234-8239, ISSN 2046-2069

DOI: 10.1039/c7ra13169k
PMID: 29552339

6 p, 708.7 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles