Quantum-Confined Optical Interband Transitions in delta-Doped Doping Superlattices.

Optical absorption and photoluminescence experiments are performed on GaAs doping superlattices, which have a delta-function- like doping profile of alternating n-type and p-type dopant sheets. Absorption and emission spectra reveal for the first time the clear signature of quantum-confined interband transitions. The peaks of the experimental absorption and luminescence spectra are assigned to calculated energies of quantum-confined transitions with very good agreement. It is shown that the employment of the delta-doping technique results in improved optical properties of doping superlattices.