Determination of the in‐plane effective mass and quantum lifetime of 2D electrons in AlGaN/GaN based HEMTs

Magnetoresistance and Hall resistance measurements have been used to investigate the electronic transport properties of AlGaN/GaN based HEMTs. The Shubnikov–de Haas (SdH) oscillations from magnetoresistance, is obtained by fitting the nonoscillatory component to a polynomial of second degree, and then subtracting it from the raw experimental data. It is shown that only first subband is occupied with electrons. The two‐dimensional (2D) carrier density and the Fermi energy with respect to subband energy ( E F – E 1 ) have been determined from the periods of the SdH oscillations. The in‐plane effective mass (m*) and the quantum lifetime ( τ q ) of electrons have been obtained from the temperature and magnetic field dependencies of the SdH amplitude, respectively. The in‐plane effective mass of 2D electrons is in the range between 0.19 m 0 and 0.22 m 0 . Our results for in‐plane effective mass are in good agreement with those reported in the literature (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)