Ristein J, Mammadov S, Seyller T (2012)
Publication Type: Journal article
Publication year: 2012
Publisher: American Physical Society
Book Volume: 108
Pages Range: 246104
DOI: 10.1103/PhysRevLett.108.246104
We explain the robust p-type doping observed for quasi-free-standing graphene on hexagonal silicon carbide by the spontaneous polarization of the substrate. This mechanism is based on a bulk property of SiC, unavoidable for any hexagonal polytype of the material and independent of any details of the interface formation. We show that sign and magnitude of the polarization are in perfect agreement with the doping level observed in the graphene layer. With this mechanism, models based on hypothetical acceptor-type defects as they are discussed so far are obsolete. The n-type doping of epitaxial graphene is explained conventionally by donorlike states associated with the buffer layer and its interface to the substrate that overcompensate the polarization doping. © 2012 American Physical Society.
APA:
Ristein, J., Mammadov, S., & Seyller, T. (2012). Origin of Doping in Quasi-Free-Standing Graphene on Silicon Carbide. Physical Review Letters, 108, 246104. https://dx.doi.org/10.1103/PhysRevLett.108.246104
MLA:
Ristein, Jürgen, Samir Mammadov, and Thomas Seyller. "Origin of Doping in Quasi-Free-Standing Graphene on Silicon Carbide." Physical Review Letters 108 (2012): 246104.
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