Effect of Growth Morphology on the Electronic Structure of Epitaxial Graphene on SiC

Michael D. Williams, Dennis W. Hess

Center of Excellence in Microelectronics and Photonics, Department of Physics, Clark Atlanta University, Atlanta, USA.
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, USA.

DOI: 10.4236/graphene.2013.21008                

Abstract

Ultraviolet photoemission spectroscopy is used to investigate the electronic structure of epitaxial graphene grown by the thermal decomposition of the carbon face of 4H SiC. We find that the growth of the film on the chemical mechanically polished and hydrogen etched surface enhances spectral features in the valence band structure compared to the film grown on an unpolished hydrogen etched substrate. This result is indicative of a more highly ordered surface structure compared to the morphologically rough material and shows that substrate preparation plays an important role in the quality of the film. The work function of the smooth surface film is found to be 0.4 eV higher than that for graphite and 0.1 eV less than for the rough surface growth.

Keywords

Graphene; SiC; UPS; Work Function; Electronic Structure

Conflicts of Interest

The authors declare no conflicts of interest.

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