Dislocation scattering in a two-dimensional electron gas of an AlxGa1-xN/GaN heterostructure

The theoretical electron mobility limited by dislocation scattering of a two-dimensional electron gas confined near the interface of an AlxGa1-xN/GaN heterostructure is calculated. The accurate wave functions and electron distributions of the three lowest subbands for a typical structure are obtained by solving the Schrodinger and Poisson equations self-consistently. Based on the model of treating dislocation as a charged line, a simple scattering potential, a square-well potential, is utilized. The estimated mobility suggests that such a choice can simplify the calculation without introducing significant deviation from experimental data. It is also found that the dislocation scattering dominates both the low- and moderate-temperature mobilities and accounts for the nearly flattening-out behavior with increasing temperature. To clarify the role of dislocation scattering all standard scattering mechanisms are included in the calculation.