The dielectric function of a GaAs/AlGaAs single quantum well: calculation and comparison with experiment

The dielectric function (DF) of a modulation doped (0 0 1) GaAs/AlGaAs (Al content of x=0.33) single quantum well structure containing a two-dimensional electron gas (2DEG) was calculated as a function of 2DEG density and temperature, taking into account the nonparabolicity of the valence band and many-body effects. The DF was used to simulate electroreflectance and photoluminescence excitation spectra. The results were found to be in a good agreement with experimental data at T>80 K and 2DEG concentrations of more than 2×10¹¹ cm⁻².