Probing the dielectric response of the interfacial buffer layer in epitaxial graphene via optical spectroscopy

Published: November 28, 2017


Heather M. Hill, Albert F. Rigosi, Sugata Chowdhury, Yanfei Yang, Nhan V. Nguyen, Francesca M. Tavazza, Randolph E. Elmquist, David B. Newell, Angela R. Hight Walker


Monolayer epitaxial graphene (EG) is a suitable candidate for a variety of electronic applications. One advantage of EG growth on the Si face of SiC is that it develops as a single crystal, as does the layer below, referred to as the interfacial buffer layer (IBL), whose properties include an electronic band gap. Though much research has been conducted to learn about the electrical properties of the IBL, not nearly as much work has been reported on the optical properties of the IBL. In this work, we combine measurements from Mueller matrix ellipsometry, differential reflectance contrast, atomic force microscopy, and Raman spectroscopy, as well as calculations from Kramers-Kronig analyses and density functional theory (DFT), to determine the dielectric function of the IBL within the energy range of 1 eV to 8.5 eV.
Citation: Physical Review B
Pub Type: Journals


epitaxial graphene, buffer layer, ellipsometry, optical dielectric functions, differential reflectance contrast, Kramers-Kronig relations
Created November 28, 2017, Updated November 28, 2017