Formation of graphene atop a Si adlayer on the C-face of SiC

Jun Li, Qingxiao Wang, Guowei He, Michael Widom, Lydia Nemec, Volker Blum, Moon Kim, Patrick Rinke, Randall M. Feenstra*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)
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Abstract

The structure of the SiC(000 (1) over bar) surface, the C-face of the {0001} SiC surfaces, is studied as a function of temperature and of pressure in a gaseous environment of disilane (Si2H6). Various surface reconstructions are observed, both with and without the presence of an overlying graphene layer (which spontaneously forms at sufficiently high temperatures). Based on cross-sectional scanning transmission electron microscopy measurements, the interface structure that forms in the presence of the graphene is found to contain 1.4-1.7 monolayers (ML) of Si, a somewhat counter-intuitive result since, when the graphene forms, the system is actually under C-rich conditions. Using ab initio thermodynamics, it is demonstrated that there exists a class of Si-rich surfaces containing about 1.3 ML of Si that are stable on the surface (even under C-rich conditions) at temperatures above similar to 400 K. The structures that thus form consist of Si adatoms atop a Si adlayer on the C-face of SiC, with or without the presence of overlying graphene.

Original languageEnglish
Article number084006
Pages (from-to)1-12
Number of pages12
JournalPhysical Review Materials
Volume3
Issue number8
DOIs
Publication statusPublished - 19 Aug 2019
MoE publication typeA1 Journal article-refereed

Keywords

  • SURFACE RECONSTRUCTIONS
  • EPITAXIAL GRAPHENE
  • MOLECULAR-DYNAMICS
  • GAN(0001)

Cite this

Li, J., Wang, Q., He, G., Widom, M., Nemec, L., Blum, V., ... Feenstra, R. M. (2019). Formation of graphene atop a Si adlayer on the C-face of SiC. Physical Review Materials, 3(8), 1-12. [084006]. https://doi.org/10.1103/PhysRevMaterials.3.084006