2025/06/19 by Radtke, Guillaume, Lazzeri, Michele
Materials Science · #Boron and Carbon Nanomaterials Research #FOS: Physical sciences #Graphene research and applications #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Thermal properties of materials
paper · pdf · doi:10.48550/arxiv.2506.16166
openalex publication_date 2025/06/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The vibrational properties of semiconducting graphene buffer layer epitaxially grown on hexagonal silicon carbide are determined using first-principles calculations on a realistic structural model. Despite the important chemical and structural disorder associated with the partial covalent bonding with the substrate, the buffer-layer carbon atoms still display quasidispersive phonons mimicking those of graphene. The related frequency softening and broadening provide a natural interpretation of the measured Raman signal. The vibrations determining thermal conduction are found to delocalize completely on the SiC substrate, leading to an effective spatial separation between material components determining, respectively, electronic and thermal transport properties. This situation opens perspectives for thermoelectric applications.