Photoluminescence study of silicon donors in<i>n</i>-type modulation-doped GaAs/AlAs quantum wells

Abstract

We have studied the photoluminescence spectra from GaAs/AlAs quantum wells doped with silicon donors in the AlAs barriers. The GaAs well width in these structures was chosen so that the lowest conduction subband ${\mathit{e}}_{1}$ lies above the donor states. An impurity-related feature is identified as the donor-to-valence-band transition. A comparison of the energy of this feature with that of the AlAs X-valley-to-valence-band transition yields the donor binding energy.