Dislocation scattering in AlxGa1−xN∕GaN heterostructures

Abstract

The theoretical electron mobility limited by dislocation scattering of a two-dimensional electron gas confined near the interface of AlxGa1−xN∕GaN heterostructures was calculated. Based on the model of treating dislocation as a charged line, an exponentially varied potential was adopted to calculate the mobility. The estimated mobility suggests that such a choice can simplify the calculation without introducing significant deviation from experimental data, and we obtained a good fitting between the calculated and experimental results. It was found that the measured mobility is dominated by interface roughness and dislocation scattering at low temperatures if dislocation density is relatively high (>109cm−2), and accounts for the nearly flattening-out behavior with increasing temperature.