Monte Carlo calculation of two-dimensional electron dynamics in GaN–AlGaN heterostructures

We present detailed Monte Carlo based calculations of the electron dynamics in GaN–AlGaN heterostructures in the presence of strain polarization fields. The model consists of a fully numerical self-consistent solution of the Schrödinger–Poisson equation with a Monte Carlo transport model. The two-dimensional sub-band energies, wave functions and carrier scattering mechanisms are computed numerically and included within a Monte Carlo simulation. The electron energy, steady-state and transient drift velocity and band occupancy are calculated as a function of electric field for different AlGaN–GaN heterostructure compositions. The effect of piezoelectrically induced strain fields on the transport dynamics is examined. A field dependent mobility model is also developed from the Monte Carlo results.