scholarly journals Hydrogen intercalation of epitaxial graphene and buffer layer probed by mid-infrared absorption and Raman spectroscopy

AIP Advances ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 045015 ◽  
Author(s):  
J. Kunc ◽  
M. Rejhon ◽  
P. Hlídek
Keyword(s):  
Raman Spectroscopy ◽  
Buffer Layer ◽  
Infrared Absorption ◽  
Epitaxial Graphene ◽  
Mid Infrared ◽  
Hydrogen Intercalation

Hydrogen Intercalation below Epitaxial Graphene on SiC(0001)

2010 ◽  
Vol 645-648 ◽  
pp. 623-628 ◽  
Author(s):  
Christian Riedl ◽  
Camilla Coletti ◽  
Takayuki Iwasaki ◽  
Ulrich Starke
Keyword(s):  
Hydrogen Bonds ◽  
Buffer Layer ◽  
Epitaxial Graphene ◽  
Monolayer Graphene ◽  
Graphene Monolayer ◽  
Free Standing ◽  
Strong Electron ◽  
Hydrogen Intercalation ◽  
Initial Carbon ◽  
N Doping

In this report we review how intrinsic drawbacks of epitaxial graphene on SiC(0001) such as n-doping and strong electronic influence of the substrate can be overcome. Besides surface transfer doping from a strong electron acceptor and transfer of epitaxial graphene from SiC(0001) to SiO2 the most promising route is to generate quasi-free standing epitaxial graphene by means of hydrogen intercalation. The hydrogen moves between the (6p3×6p3)R30◦ reconstructed initial carbon (so-called buffer) layer and the SiC substrate. The topmost Si atoms which for epitaxial graphene are covalently bound to this buffer layer, are now saturated by hydrogen bonds. The buffer layer is turned into a quasi-free standing graphene monolayer, epitaxial monolayer graphene turns into a decoupled bilayer. The intercalation is stable in air and can be reversed by annealing to around 900 °C. This technique offers significant advances in epitaxial graphene based nanoelectronics.

Decoupling the Graphene Buffer Layer from SiC(0001) via Interface Oxidation

2012 ◽  
Vol 717-720 ◽  
pp. 649-652 ◽  
Author(s):  
Markus Ostler ◽  
Roland J. Koch ◽  
Florian Speck ◽  
Felix Fromm ◽  
Hendrik Vita ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Buffer Layer ◽  
Graphene Layer ◽  
Epitaxial Graphene ◽  
Decoupling Effect ◽  
Spectroscopy Studies ◽  
Induced Defects ◽  
Covalently Bound

Epitaxial graphene (EG) grown on SiC(0001) resides on the so-called buffer layer. This carbon rich (6√3×6√3)R30° reconstruction is covalently bound to the topmost silicon atoms of the SiC. Decoupling the graphene buffer layer from the SiC interface is a well studied topic since successful intercalation has been shown for hydrogen [1-3]. Recently, intercalation was also shown for oxygen [4, 5]. We present ARPES, XPS and Raman spectroscopy studies to determine the quality of oxygen intercalated buffer layer samples in terms of decoupling and integrity of the transformed graphene layer. The decoupling effect is demonstrated by ARPES measurements showing a graphene-like π band. XPS shows whether the oxidation takes place in the buffer layer or at the interface. Raman spectroscopy is well suited to investigate oxygen induced defects in graphene-like material.

Pinned and unpinned epitaxial graphene layers on SiC studied by Raman spectroscopy

2012 ◽  
Vol 111 (11) ◽  
pp. 114307 ◽  
Author(s):  
K. Grodecki ◽  
J. A. Blaszczyk ◽  
W. Strupinski ◽  
A. Wysmolek ◽  
R. Stępniewski ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Epitaxial Graphene ◽  
Graphene Layers

Tuning a Schottky barrier of epitaxial graphene/4H-SiC (0001) by hydrogen intercalation

2016 ◽  
Vol 108 (5) ◽  
pp. 051605 ◽  
Author(s):  
P. Dharmaraj ◽  
P. Justin Jesuraj ◽  
K. Jeganathan
Keyword(s):  
Schottky Barrier ◽  
Epitaxial Graphene ◽  
Hydrogen Intercalation

scholarly journals Photogenerated Carriers in SrTiO3Probed by Mid-Infrared Absorption

2006 ◽  
Vol 75 (2) ◽  
pp. 023703 ◽  
Author(s):  
Hidekazu Okamura ◽  
Masato Matsubara ◽  
Koichiro Tanaka ◽  
Kazutoshi Fukui ◽  
Mitsushi Terakami ◽  
...  
Keyword(s):  
Infrared Absorption ◽  
Mid Infrared

scholarly journals Clinical applications of infrared and Raman spectroscopy: state of play and future challenges

The Analyst ◽  
2018 ◽  
Vol 143 (8) ◽  
pp. 1735-1757 ◽  
Author(s):  
Matthew J. Baker ◽  
Hugh J. Byrne ◽  
John Chalmers ◽  
Peter Gardner ◽  
Royston Goodacre ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Absorption ◽  
State Of The Art ◽  
Clinical Applications ◽  
The State ◽  
Infrared And Raman Spectroscopy ◽  
Future Challenges

This review examines the state-of-the-art of clinical applications of infrared absorption and Raman spectroscopy, outstanding challenges, and progress towards translation.

Raman Spectroscopy of Epitaxial Si/Si1-xGe, xHeterostructures

1998 ◽  
Vol 533 ◽  
Author(s):  
Ran Liu ◽  
Stefan Zollner ◽  
Ming Liaw ◽  
David O'meara ◽  
Nigel Cave
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Raman Scattering ◽  
Buffer Layer ◽  
Excellent Agreement ◽  
Lattice Mismatch ◽  
Theoretical Curve ◽  
Sum Rule ◽  
Si Substrates ◽  
Strain Coefficient

AbstractRaman scattering studies were carried out on epi Si/Si1-xGex (x = 0.1 to 0.3) heterostructures consisting of a thin Si cap layer (100 - 400 A˚), a grade-down Si1-xGex layer, a constant Si1-xGex, buffer layer and a grade-up graded Si1-xGex layer on (100) oriented Si substrates. Different Ge composition, Si1-xGex layer thicknesses and thermal treatment were used to achieve different relaxation in the Si1-xGex layers. It has been revealed that, to a very good approximation, the absolute strains in the cap Si and constant Si1-xGex layers follow a simple sum-rule that is imposed by the lattice mismatch between unstrained Si and completely relaxed Si1-x Gex. This sum rule can be used to determine the Ge composition and stresses in both cap Si and constant Si1-xGex layers. Excellent agreement was found between the theoretical curve obtained with LO phonon strain coefficient b=−930cm−1 and the experimental total strain for all samples, regardless of the degree of the relaxation of the grade-up Si1-xGex layer.

Sign in / Sign up

Export Citation Format

Share Document