Photoluminescence spectra of doping superlattices.

Pulsed and cw photoluminescence measurements have been performed on a variety of GaAs doping superlattices with unequal n- and p-doping levels. At 6 K, samples with a p- to n-type dopant ratio greater than 2 and potential well depths between 150 and 500 meV exhibit a two-peak spectrum over a range of excitation intensities sufficient to generate enough carriers to partially compensate the internal electric potential. The peak separation is dependent on the superlattice parameters and scales with the depth of the potential wells.