title: Self-Terminating Confinement Approach for Large-Area Uniform Monolayer Graphene Directly over Si/SiOxby Chemical Vapor Deposition.
abstract: To synthesize graphene by chemical vapor deposition (CVD) both in large area and with uniform layer number directly over Si/SiOxhas proven challenging. The use of catalytically active metal substrates, in particular Cu, has shown far greater success and therefore is popular. That said, for electronics applications it requires a transfer procedure, which tends to damage and contaminate the graphene. Thus, the direct fabrication of uniform graphene on Si/SiOxremains attractive. Here we show a facile confinement CVD approach in which we simply "sandwich" two Si wafers with their oxide faces in contact to form uniform monolayer graphene. A thorough examination of the material reveals it comprises faceted grains despite initially nucleating as round islands. Upon clustering, they facet to minimize their energy. This behavior leads to faceting in polygons, as the system aims to ideally form hexagons, the lowest energy form, much like the hexagonal cells in a beehive, which requires the minimum wax. This process also leads to a near minimal total grain boundary length per unit area. This fact, along with the high graphene quality, is reflected in its electrical performance, which is highly comparable with graphene formed over other substrates, including Cu. In addition, the graphene growth is self-terminating. Our CVD approach is easily scalable and will make graphene formation directly on Si wafers competitive against that from metal substrates, which suffer from transfer. Moreover, this CVD route should be applicable for the direct synthesis of other 2D materials and their van der Waals heterostructures.
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.
authors.forename: Jinbo
authors.identifier: 0000-0001-6965-4166
authors.initials: J
authors.lastname: Pang
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Mendes
authors.affiliation: Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Pawel S
authors.initials: PS
authors.lastname: Wrobel
authors.affiliation: Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Michal D
authors.initials: MD
authors.lastname: Wlodarski
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.|Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Huy Quang
authors.initials: HQ
authors.lastname: Ta
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.
authors.forename: Lars
authors.identifier: 0000-0002-6703-8447
authors.initials: L
authors.lastname: Giebeler
authors.affiliation: Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Trzebicka
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gemming
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan, 430072, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Fu
authors.affiliation: Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Zhongfan
authors.identifier: 0000-0003-0065-7988
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Erich Schmid Institute of Materials Science, Austrian Academy of Sciences , Jahnstraße 12, A-8700 Leoben, Austria.|Department Materials Physics, Montanuniversität Leoben , Jahnstraße 12, A-8700 Leoben, Austria.
authors.forename: Juergen
authors.initials: J
authors.lastname: Eckert
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.|Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Bachmatiuk
authors.affiliation: IFW-Dresden , Helmholtz Strasse 20, D-01171 Dresden, Germany.|Centre of Polymer and Carbon Materials, Polish Academy of Sciences , ul. M. Curie-Sklodowskiej 34, Zabrze, PL-41-819 Zabrze, Poland.
authors.forename: Mark H
authors.identifier: 0000-0002-4448-1569
authors.initials: MH
authors.lastname: Rümmeli
keywords: carrier mobility; chemical vapor deposition; direct monolayer graphene growth; grain boundaries; optical transmission; silicon; uniform graphene