Screening effects on the mobility properties in AlGaN/GaN heterostructures with varied Al content

The electron mobility at a AlGaN/GaN heterostructure is calculated using an ensemble Monte Carlo (MC) technique where the emphasis is primarily given to screening effects and dislocation scattering. Calculations of electron steady-state velocity-field curves confirm that screening has significant effects on the transport properties of AlGaN/GaN heterostructures. The mobility calculations are obtained for Al-content (8–35%), thickness of AlGaN barrier (30–500[Formula: see text]Å) and for various temperatures (77–1000[Formula: see text]K). Based on our theoretical scattering rates calculations, we show that screening effects should be included for all scattering rates to obtain good agreement with experimental results. Besides, especially dislocation scattering should be taken into account to get mobility results that agree with experiments at low field values. Our overall results agree reasonably well with experimental studies. These results can be highly useful in design and optimization of GaN-based devices.