Paper EL+AS+EM+MS+TF-FrM7
Spectroscopic Ellipsometry on Graphene
Friday, October 22, 2010, 10:20 am, Room Cochiti
| Session: |
Spectroscopic Ellipsometry - Inorganic Thin Films |
| Presenter: |
J.W. Weber, Eindhoven University of Technology, Netherlands |
| Authors: |
J.W. Weber, Eindhoven University of Technology, Netherlands
V.E. Calado, Delft University of Technology, Netherlands
M.C.M. van de Sanden, Eindhoven University of Technology, Netherlands
|
| Correspondent: |
Click to Email |
We show how we used spectroscopic ellipsometry to determine both the optical constants and thickness of graphene1. We scanned a mechanically exfoliated graphene flake (150 x 380 μm) on an oxidized silicon wafer (98 nm SiO2) with a spectroscopic ellipsometer with a focused spot (100 x 55 μm) at an angle of 55°, in the range 210-1000 nm. The spectroscopic ellipsometric data were analyzed with an optical model in which the optical constants of graphene were parameterized by B-splines.2,3 This parameterization was key in the uncorrelated, accurate and simultaneous determination of the optical constants and thickness of graphene. The thickness is in perfect agreement with the thickness as expected from the interlayer spacing in graphite: 3.4 Å. This work opens up the possibility for in situ monitoring of graphene growth.
References
[1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, and A. A. Firsov, Science 306, 666 (2004).
[2] B. Johs and J. S. Hale, Phys. Status Solidi A 205, 715 (2008).
[3] J. W. Weber, T. A. R. Hansen, M. C. M. van de Sanden, and R. Engeln, J. Appl. Phys. 106, 123503 (2009).