Subband electron properties of modulation-doped Al_xGa_1-xN/GaN heterostructures with different barrier thicknesses

Magnetotransport properties of modulation-doped heterostructures with different barrier thickness were analyzed in magnetic fields. The elastic strain relaxation of the barrier on subband electron densities and mobilities in the heterostructures was also analyzed using fast fourier transform (FFT). The densities and mobilities of individual subbands were derived by analyzing Shubnikov-de Hass measurements (SdH) oscillations. The results revealed that elastic strain relaxation has strong effects on mobilities of the excited states.