Momentum relaxation of electrons in n-type bulk GaN

Abstract

We report on Hall mobility and carrier density measurements on n-type GaN epilayers grown on sapphire by MBE. The results are discussed using a theoretical model that takes into account the most important scattering mechanisms contributing to determining the mobility of electrons in 3D. We show that polar–optical phonon scattering and dislocation scattering dominate at high temperatures especially in samples with low carrier density, while impurity and dislocation scattering take over at low temperatures.