Low-Temperature Transport in AlGaN/GaN 2D Electron Systems

In this work results of magnetotransport investigation in a two-dimensional electron gas (2DEG) formed at the interface of an undoped GaN/AlGaN heterostructure are reported. The measurements were performed in wide temperature (from 300 mK to 10 K), and magnetic field (up to 10 T) range. The effective mass of investigated 2DEG were estimated from Shubnikov-de-Haas oscillation measurements and found to be as high as 0.265 me. The experimental data are analyzed within the framework of weak localization and interference corrections to conductivity together with alternative mechanisms specific for polar semiconductors taking into account a strong electron-optical phonon interaction.