Theory and Computation of Hall Scattering Factor in Graphene.

The Hall scattering factor, , is a key quantity for establishing carrier concentration and drift mobility from Hall measurements; in experiments, it is usually assumed to be 1. In this paper, we use a combination of analytical and modeling to determine in graphene. Although at high carrier densities ≈ 1 in a wide temperature range, at low doping the temperature dependence of is very strong with values as high as 4 below 300 K. These high values are due to the linear bands around the Dirac cone and the carrier scattering rates due to acoustic phonons. At higher temperatures, can instead become as low as 0.5 due to the contribution of both holes and electrons and the role of optical phonons. Finally, we provide a simple analytical model to compute accurately in graphene in a wide range of temperatures and carrier densities.