The active layers of single quantum-well separate confinement heterostructure lasers which had been grown by means of molecular beam epitaxy were investigated by using photoluminescence absorption spectroscopy, secondary ion mass spectroscopy, capacitance-voltage profiling and laser threshold current measurements. It was found that a significant amount of Be diffusion occurred under normal growth conditions. Large concentrations of Be in the quantum well were correlated with the lack of an exciton feature in the absorption spectrum. The amount of Be in the active region was reduced by reducing the Be concentration and by decreasing the growth temperature in the upper cladding region of the laser.

Beryllium Diffusion in GaAs/AlGaAs Single Quantum Well Separate Confinement Heterostructure Laser Active Regions. G.E.Kohnke, M.W.Koch, C.E.C.Wood, G.W.Wicks: Applied Physics Letters, 1995, 66[21], 2786-8