Investigation of impurity variations by cathodoluminescence imaging: Application to GaSb:Te

Publisher Website
Google Scholar
Abstract
Crystals grown by the Czochralski technique frequently exhibit periodic variations of impurity concentration. These growth striations are microscopic in size and provide detailed information on the growth conditions. Although these striations are easily revealed by chemical etching, quantitative changes in carrier concentration are not easily determined. In this letter, the cathodoluminescence (CL), efficiency of GaSb:Te crystals is presented as a function of carrier concentration. The periodic variations in CL intensity, spatially correlated with growth striations revealed by an etchant, corresponds to ∼20% changes in carrier concentration. Finally, within the resolution of the CL technique, no evidence of a second phase is found in GaSb crystals doped with Te to the solubility limit.