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Title: New X-ray insight into oxygen intercalation in epitaxial graphene grown on 4H-SiC(0001)

Efficient control of intercalation of epitaxial graphene by specific elements is a way to change properties of the graphene. Results of several experimental techniques, such as X-ray photoelectron spectroscopy, micro-Raman mapping, reflectivity, attenuated total reflection, X-ray diffraction, and X-ray reflectometry, gave a new insight into the intercalation of oxygen in the epitaxial graphene grown on 4H-SiC(0001). These results confirmed that oxygen intercalation decouples the graphene buffer layer from the 4H-SiC surface and converts it into the graphene layer. However, in contrast to the hydrogen intercalation, oxygen does not intercalate between carbon planes (in the case of few layer graphene) and the interlayer spacing stays constant at the level of 3.35–3.32 Å. Moreover, X-ray reflectometry showed the presence of an oxide layer having the thickness of about 0.8 Å underneath the graphene layers. Apart from the formation of the nonuniform thin oxide layer, generation of defects in graphene caused by oxygen was also evidenced. Last but not least, water islands underneath defected graphene regions in both intercalated and non-intercalated samples were most probably revealed. These water islands are formed in the case of all the samples stored under ambient laboratory conditions. Water islands can be removed from underneath the few layer graphene stacksmore » by relevant thermal treatment or by UV illumination.« less
Authors:
;  [1] ; ; ; ;  [2] ;  [1] ;  [3]
  1. Faculty of Physics, University of Warsaw, Hoża 69, 00-681 Warsaw (Poland)
  2. Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland)
  3. (Poland)
Publication Date:
OSTI Identifier:
22399270
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CLATHRATES; CRYSTAL GROWTH; CRYSTAL STRUCTURE; EPITAXY; GRAPHENE; HEAT TREATMENTS; LAYERS; MAPPING; OXIDES; OXYGEN; RAMAN SPECTROSCOPY; REFLECTIVITY; SILICON CARBIDES; SPECTRAL REFLECTANCE; SURFACES; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY