Optical constants of graphene measured by spectroscopic ellipsometry

J. W. Weber, V. E. Calado, M. C. M. van de Sanden
2010 Applied Physics Letters  
A mechanically exfoliated graphene flake ͑ϳ150ϫ 380 m 2 ͒ on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ͑ϳ100 ϫ 55 m 2 ͒ at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the optical constants were parameterized by B-splines. This parameterization is the key for the simultaneous accurate determination of the optical constants in the wavelength range 210-1000 nm and the
more » ... -1000 nm and the thickness of graphene, which was found to be 3.4 Å.
doi:10.1063/1.3475393 fatcat:52g5hf3gwbhprf74hw7i3ftrhq