Steady-state electron transport in the III–V nitride semiconductors: A sensitivity analysis

We studied the sensitivity of the steady-state electron transport in GaN to variations in the important material parameters related to the band structure. We found (a) that an increase in the lowest conduction-band-valley effective mass leads to a lowering and broadening of the peak in the velocity-field characteristic, as well as to an increase in the field at which the peak occurs; (b) that increases in the upper conduction-band-valley effective masses dramatically decrease the saturation drift velocity, with very little other effect; (c) that increased nonparabolicity of the lowest conduction-band valley leads to a broadening and shifting to higher electric fields of the peak in the velocity-field characteristic; (d) that increases in the intervalley energy separation lead to moderate increases in the peak drift velocity; and (e) that increases in the degeneracy of the upper conduction-band valleys leads to a moderate decrease in the saturation drift velocity.