MAGNETOTRANSPORT STUDY ON THE 2-DIMENSIONAL ELECTRON-GAS IN ALGAN GANHETEROSTRUCTURES/

We have performed magnetotransport studies on AlGaN/GaN heterostructur es at low temperature and magnetic field up to 30 T. The integer quant um Hall effect is observed in two-dimensional electron gas at the AlGa N/GaN interface, From the temperature dependence of the low-field Shub nikov-de Hass oscillations, a carrier effective mass of m = 0.228m(e) is obtained. Dingle plots of our resistivity data show inhomogeneity in the two-dimensional electron gas. Finally, we found that for electr onic density as high as 5.47 X 10(12) cm(-2), only the lowest subband in the quantum well is occupied. (C) 1998 American Institute of Physic s. [S0003-6951(98)02936-2].