Abstract
We have performed Shubnikov-de Haas (SdH) and Hall effect measurements to investigate the electronic transport properties of polarisation induced 2DEGs in AlxGa1—xN/GaN heterostructures with alloy compositions between x = 0.10 and 0.35 and sheet carrier concentrations of up to ns = 1.05 × 1013 cm—2. From SdH measurements of 2DEGs with sheet carrier concentrations of 2.1 × 1012 and 4.6 × 1012 cm—2, effective electron masses were determined to be 0.24 and 0.207m0, respectively. In addition, angle resolved SdH measurements were performed to evaluate the effective g-factor from the angle of zero oscillation amplitude. Including the measured electron masses, the g-factors were calculated to be 2.11 and 2.47, respectively. In order to identify the main electron scattering mechanism we determined the ratio between transport- and quantum scattering times as a function of sheet carrier concentration. We observe a significant decrease of the tt/tq ratio with increasing 2DEG carrier concentration, indicating a transition from a dominant small angle to large angle scattering mechanism when ns exceeds 7 × 1012 cm—2.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
