Localization of Y Luminescence at Glide Dislocations in Cadmium Telluride

(Received 3 October 1996, revised 23 December 1996 accepted 17 March 1997)

Abstract
We demonstrate unambiguously that the well-known defect-related Y luminescence band at 1.476 eV in CdTe originates from the polar Te(g) glide dislocation segments. Crystallographically defined glide dislocation arrangements produced by local plastic deformation on ( )Te surfaces using Vickers microindentation were characterized by temperature-dependent cathodoluminescence (CL) microscopy as well as CL and PL spectroscopy. The identification of the Te(g) dislocation was obtained by determining the surface polarity applying X-ray diffraction and subsequently revealing the volume glide geometry observed by CL imaging after stepwise depth-etching of the ( ) sample surface. From the spectral and recombination-kinetic properties of the dislocation-bound Y luminescence the model of radiative decay of dislocation-related excitons is supported. Particularly, we may conclude that they are bound to energy levels in the fundamental gap localized at the 90° Te(g) partial dislocations.