Observations on subband electron properties in In_0.65Ga_0.35As/ In_0.52Al_0.48As MM-HEMT with Si δ-doped on the barriers

Magneto-transport measurements have been carried out on a Si δ-doped In_0.65Ga_0.35As/ In_0.52Al_0.48As metamorphic high-electron-mobility transistor with InP substrate in a temperature range between 1.5 and 60 K under magnetic field up to 13 T. We studied the Shubnikov-de Haas (SdH) effect and the Hall effect for the In_0.65Ga_0.35As/ In_0.52Al_0.48As As single quantum well occupied by two subbands and obtained the electron concentration and energy levels respectively. We solve the Schrödinger-Kohn-Sham equation in conjunction with the Poisson equation self-consistently and obtain the configuration of conduction band, the distribution of carriers concentration, the energy level of every subband and the Fermi energy. The calculational results are well consistent with the results of experiments. Both experimental and calculational results indicate that almost all of the δ-doped electrons transfer into the quantum well in the temperature range between 1.5 and 60 K.