Mobility in epitaxial GaN: Limitation of electron transport due to dislocation walls

Abstract

A theoretical model to explain the sharp transition to low-mobility regime in n-type GaN layers is proposed. We show that this peculiarity of the mobility versus free carrier concentration can be interpreted with the well-known Read model when the scattering due to charged dislocation walls is included in consideration. An agreement with experiments is found above the critical value of carrier density.