Extraction and scattering analyses of 2D and bulk carriers in epitaxial graphene-on-SiC structure

• Mixed conduction in graphene on the SiC system is extracted.
• Scattering analyses of 2D carrier of graphene and 3D carrier of SiC were carried out.
• Mobility components and some phonon related parameters were calculated.
• A mobility component is suggested to be related to the graphene/SiC interaction.

Hall effect measurements of a graphene-on-SiC system were carried out as a function of temperature (1.8–200 K) at a static magnetic field (0.5 T). With the analysis of temperature dependent single-field Hall data with the Simple Parallel Conduction Extraction Method (SPCEM), bulk and two-dimensional (2D) carrier densities and mobilities were extracted successfully. Bulk carrier is attributed to SiC substrate and 2D carrier is attributed to the graphene layer. For each SPCEM extracted carrier data, relevant three-dimensional or 2D scattering analyses were performed. Each SPCEM extracted carrier data were explained with the related scattering analyses. A temperature independent mobility component, which may related to an interaction between graphene and SiC, was observed for both scattering analyses with the same mobility limiting value. With the SPCEM, effective ionized impurity concentration of SiC substrate, extracted 2D-mobility, and sheet carrier density of the graphene layer are calculated with using temperature dependent static magnetic field Hall data.

The Simple Parallel Conduction Extraction Method (SPCEM) was used to extract mixed conduction in graphene on the SiC system. Extracted conduction channels related to graphene and bulk SiC layers were found. With the proper scattering analyses, mobility components of different mechanisms and some phonon related parameters were calculated. In addition to used scattering mechanisms, which are special to graphene or SiC layers, a temperature independent mobility component was observed in both scattering analyses with the same mobility limiting value. This mobility component is suggested to be related to the graphene/SiC interaction.Figure optionsDownload as PowerPoint slide