Aqueous-Phase Oxidation of Epitaxial Graphene on the Silicon Face of SiC(0001)
| Autor: | Maisarah B. A. Razak, Jun Yoshinobu, Sumio Hosaka, Kozo Mukai, Hayato Sone, Mark C. Hersam, Takanori Koitaya, Zakir Hossain, Shinya Yoshimoto |
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| Rok vydání: | 2013 |
| Předmět: |
Materials science
Silicon Graphene Band gap Scanning tunneling spectroscopy Analytical chemistry chemistry.chemical_element Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention symbols.namesake General Energy X-ray photoelectron spectroscopy chemistry Chemical engineering law Oxidizing agent symbols Physical and Theoretical Chemistry Scanning tunneling microscope Raman spectroscopy |
| Zdroj: | The Journal of Physical Chemistry C. 118:1014-1020 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | To explore the chemical and electronic states of oxidized epitaxial graphene (EG) grown on the Si face of SiC(0001), we employ the Hummers oxidizing agents (H2SO4 + NaNO3 + KMnO4) under different reaction conditions that oxidize the graphene layer. The resulting material is characterized with scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). A mild “drop-cast” procedure at 60 °C is found to be equally effective at oxidizing EG as the conventional Hummers procedure. This aqueous-phase oxidation reaction appears to proceed in an autocatalytic manner as indicated by the concurrent observation of patches of oxidized and clean graphene areas in atomically resolved STM images on partially oxidized EG. STS further reveals substantial changes in electronic structure for oxidized EG including the opening of a local band gap of ∼0.4 eV. The oxidation is confined to the graphene layers as verified by XPS characterization of the... |
| Databáze: | OpenAIRE |
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