Decoration of extended defects in GaSb by Al doping as evidenced by cathodoluminescence studies

Abstract

The effect of aluminium on the defect structure of GaSb crystals, grown by the vertical Bridgman technique, has been investigated by cathodoluminescence (CL) in the scanning electron microscope. Crystals have been found to be highly homogeneous along the growth axis with the exception of the top end which showed Al accumulation. The CL results show decoration of extended defects by Al but contrary to the case of other dopants Al has not been found to cause a significative reduction of native accepters. A CL band at about 850 meV appears to be related to the presence of aluminium.