Energy relaxation probed by weak antilocalization measurements in GaN heterostructures Available to Purchase

Energy relaxation and electron-phonon (e-p) interaction are investigated in wurtzite $Al0.15Ga0.85N/AlN/GaN$ and $Al0.83In0.17N/AlN/GaN$ heterostructures with polarization induced two-dimensional electron gases in the Bloch–Grüneisen regime. Weak antilocalization (WAL) and Shubnikov–de Haas measurements were performed on gated Hall bar structures at temperatures down to 0.3 K. We used WAL as a thermometer to measure the electron temperature $Te$ as a function of the dc bias current. We found that the power dissipated per electron, $Pe$⁠, was proportional to $Te4$ due to piezoelectric acoustic phonon emission by hot electrons. We calculated $Pe$ as a function of $Te$ without any adjustable parameters for both the static and the dynamic screening cases of piezoelectric e-p coupling. In the temperature range of this experiment, the static screening case was expected to be applicable; however, our data was in better agreement with the dynamic screening case.