Interfacial Charge States in Graphene on SiC Studied by Noncontact Scanning Nonlinear Dielectric Potentiometry

Kohei Yamasue, Hirokazu Fukidome, Kazutoshi Funakubo, Maki Suemitsu, Yasuo Cho

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

We investigate pristine and hydrogen-intercalated graphene synthesized on a 4H-SiC(0001) substrate by using noncontact scanning nonlinear dielectric potentiometry (NC-SNDP). Permanent dipole moments are detected at the pristine graphene-SiC interface. These originate from the covalent bonds of carbon atoms of the so-called buffer layer to the substrate. Hydrogen intercalation at the interface eliminates these covalent bonds and the original quasi-(6×6) corrugation, which indicates the conversion of the buffer layer into a second graphene layer by the termination of Si bonds at the interface. NC-SNDP images suggest that a certain portion of the Si dangling bonds remains even after hydrogen intercalation. These bonds are thought to act as charged impurities reducing the carrier mobility in hydrogen-intercalated graphene on SiC.

Original languageEnglish
Article number226103
JournalPhysical Review Letters
Volume114
Issue number22
DOIs
Publication statusPublished - 2015 Jun 4

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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