EFFICIENT ER LUMINESCENCE-CENTERS FORMED IN GAAS BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION WITH OXYGEN CODOPING

Er-doped GaAs is grown by low-pressure metalorganic chemical vapor dep osition with and without oxygen codoping. Optically efficient Er-oxyge n complex centers are formed when a small amount of oxygen is present in the growth atmosphere. In situ monitoring of the surface morphology by light scattering from the growing surface with and without oxygen codoping suggests that migration of Er atoms on the surface is pinned by the formation of an Er-oxygen complex. We speculate that this effec t suppresses the formation of Er-rich clusters and allows the formatio n of a high concentration of uniformly dispersed Er-oxygen complex cen ters that have a high luminescence efficiency.