In this work we shed light on the early stage of the chemical vapor deposition of graphene on Ge(001) surfaces. By a combined use of μ-Raman and x-ray photoelectron spectroscopies, and scanning tunneling microscopy and spectroscopy, we were able to individuate a carbon precursor phase to graphene nucleation which coexists with small graphene domains. This precursor phase is made of C aggregates with different size, shape and local ordering which are not fully sp2 hybridized. In some atomic size regions these aggregates show a linear arrangement of atoms as well as the first signature of the hexagonal structure of graphene. The carbon precursor phase evolves in graphene domains through an ordering process, associated to a re-arrangement of the Ge surface morphology. This surface structuring represents the embryo stage of the hills-and-valleys faceting featured by the Ge(001) surface for longer deposition times, when the graphene domains coalesce to form a single layer graphene film.

Di Gaspare, L., Scaparro, A.M., Fanfoni, M., Fazi, L., Sgarlata, A., Notargiacomo, A., et al. (2018). Early stage of CVD graphene synthesis on Ge(001) substrate. CARBON, 134, 183-188 [10.1016/j.carbon.2018.03.092].

Early stage of CVD graphene synthesis on Ge(001) substrate

L. Di Gaspare
;
A. M. Scaparro;A. Notargiacomo;COLETTI, CHIARA;M. De Seta
2018-01-01

Abstract

In this work we shed light on the early stage of the chemical vapor deposition of graphene on Ge(001) surfaces. By a combined use of μ-Raman and x-ray photoelectron spectroscopies, and scanning tunneling microscopy and spectroscopy, we were able to individuate a carbon precursor phase to graphene nucleation which coexists with small graphene domains. This precursor phase is made of C aggregates with different size, shape and local ordering which are not fully sp2 hybridized. In some atomic size regions these aggregates show a linear arrangement of atoms as well as the first signature of the hexagonal structure of graphene. The carbon precursor phase evolves in graphene domains through an ordering process, associated to a re-arrangement of the Ge surface morphology. This surface structuring represents the embryo stage of the hills-and-valleys faceting featured by the Ge(001) surface for longer deposition times, when the graphene domains coalesce to form a single layer graphene film.
2018
Di Gaspare, L., Scaparro, A.M., Fanfoni, M., Fazi, L., Sgarlata, A., Notargiacomo, A., et al. (2018). Early stage of CVD graphene synthesis on Ge(001) substrate. CARBON, 134, 183-188 [10.1016/j.carbon.2018.03.092].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/335199
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