Diffusion thermopower in graphene

Abstract

The diffusion thermopower, S d, in graphene is studied for T<300K. The electron scattering mechanisms considered are those by impurities, vacancies, surface roughness, and acoustic and optical phonons via deformation potential couplings. Numerical calculations of S d performed using the semiclassical Mott relation show S d to increase almost linearly with temperature and to be determined mainly by vacancy and impurity scatterings. As function of carrier concentration, a change in sign of S d is observed. Our preliminary analysis of recent thermopower data obtains a good fit. A detailed analysis of data will provide a better understanding of electron-phonon interaction in graphene. © 2011 American Institute of Physics.