Intermixing of GaInP/GaAs multiple quantum wells

The intermixing of GaInP-GaAs superlattices induced by a heat treatment is investigated as a function of the annealing temperature and duration. Photoluminescence experiments reveal a large red shift of the effective band gap of the annealed quantum wells thus indicating a dominant self-diffusion of the group III atoms which is confirmed by secondary ion mass spectroscopic measurements. For long enough annealing durations, the red shift saturates and even decreases due to the competing slower self-diffusion of the group V atoms. Experiments are well understood based on a simple diffusion model.