Abstract
The van de Waals heterostructure formed by an epitaxial trilayer graphene is of particular interest due to its unique tunable electronic band structure and stacking sequence. However, to date, there has been a lack in the fundamental understanding of the electronic properties of epitaxial trilayer graphene. Here, we investigate the electronic properties of large-area epitaxial trilayer graphene on a 4° off-axis SiC(0001) substrate. Micro-Raman mappings and atomic force microscopy (AFM) confirmed predominantly trilayer on the sample obtained under optimized conditions. We used angle-resolved photoemission spectroscopy (ARPES) and Density Functional Theory (DFT) calculations to study in detail the structure of valence electronic states, in particular the dispersion of π bands in reciprocal space and the exact determination of the number of graphene layers. Using far-infrared magneto-transmission (FIR-MT), we demonstrate, that the electron cyclotron resonance (CR) occurs between Landau levels with a (B)1/2 dependence. The CR line-width is consistent with a high Dirac fermions mobility of ~3000 cm2·V−1·s−1 at 4 K.
Highlights
Resulting in graphene which is not suitable for device oriented applications
This is mainly due to the fact that graphene growth is easier to control on the Si-face, and under optimized conditions the thickness of the graphene can be limited to just a mono, bi and few layers over large areas
The high quality of the graphene layers was further confirmed by atomic force microscopy (AFM), micro-Raman mappings and X-ray photoelectron spectroscopy (XPS) measurements
Summary
Mahdi Hajlaoui[1,2], Haikel Sediri[1], Debora Pierucci[1], Hugo Henck[1], Thanyanan Phuphachong[3], Mathieu G. We investigate the electronic properties of large-area epitaxial trilayer graphene on a 4° off-axis SiC(0001) substrate. Lalmi et al.[11] studied trilayer graphene on 4H-SiC(0001) using STM/STS and ARPES They showed the presence of a different types of structural defect[11] in which a transition from ABA to ABC stacking was observed. The low intensity of the D peak shows that there were only a small number of defects or disorders in the graphene structure[13,14] This is an indication of the high quality of epitaxial trilayer graphene on off-axis SiC under argon flux. Uniform graphene overlayer, the graphene thickness can be calculated from the ratio between the intensity of the G and SiC components[17] extracted from XPS data using the following relation:
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