Etch pit density in single crystal CdZnTe and CdTe correlated with growth parameters

Abstract

Surface dislocations were revealed in single crystal CdZnTe and CdTe samples using chemical etching. Dislocation etch pits on the Te dominant (111)B face were studied under optical, infrared and scanning electron microscopes. The samples came from crystal ingots which were grown using different chemical compositions and applied growth parameters. From these ingots, etch pit density, shape and distribution were examined and compared with the varying growth techniques. Resistivity and mobility-lifetime product, μτe, properties of the detectors were measured. A combination of detector grade and non-detector grade ingots were tested. Near infra-red microscopy was used to compare the amount of secondary phases present in the bulk of the crystals with dislocation etch pits on their surface.