Current transport in Pt Schottky contacts to a-plane n-type GaN

The temperature-dependent electrical properties of Pt Schottky contacts to nonpolar a-plane n-type GaN were investigated. Barrier height and ideality factor, estimated from the conventional thermionic emission model, were highly temperature dependent. A notable deviation from the theoretical Richardson constant value was also observed in the conventional Richardson plot. Analyses using the thermionic field emission model showed that consideration of defect-assisted tunnelling was necessary to explain the observed electrical behaviours.