Thermoelectric transport properties of semiconductor film-based epitaxial monolayer graphene

ABSTRACT Epitaxial graphene on semiconductor films has potential for various applications due to its thermoelectric properties. We investigated factors affecting its thermo power using a solid-state physics approach, considering the interaction between the substrate and graphene, and exploring the effects of chemical potential, temperature, anharmonic vibrations of atoms, phonon-drag, and film thickness. Our results show that anharmonic effects significantly enhance the thermopower caused by electrons, especially at higher temperatures. Additionally, we observed an increase in total thermopower due to phonon-drag, although it has negligible effects at or above room temperature. We found that the thermopower on size-quantized semiconductor films is significantly higher than on metal conductor films and bulk semiconductor substrates. Decreasing the film thickness further increases the thermo power, providing an effective way to enhance the thermo electric properties of epitaxial graphene. Our findings contribute to a better understanding of the thermoelectric properties of epitaxial graphene on semiconductor films and offer valuable insights for future applications.