Single crystals having various Er concentrations were studied using cathodoluminescence in a scanning electron microscope. Low Er doping levels were found to reduce the concentration of native acceptors. In crystals with higher Er concentrations, Er-Sb precipitates formed and doping became less efficient in suppressing acceptors.

Effect of erbium doping on the defect structure of GaSb crystals P.Hidalgo, B.Méndez, J.Piqueras, J.Plaza, E.Diguez: Semiconductor Science and Technology, 1998, 13[12], 1431-3