Localization of Y Luminescence at Glide Dislocations in Cadmium Telluride

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 (iii)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 ddfraction and subsequently revealing the volume glide geometry observed by CL imaging after stepwise depth-etching of the ii it 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 1.

Optical property analysis of CZT:In single crystals after annealing by a two-step method

“…Seto et al [24] have observed a strong correlation between the intensity of the PL band and the dislocation density. This has been confirmed by Hildebrandt et al [25], who used Vickers microindentation to show that the D 2 luminescence band originates from the radiative decay of excitons bound to Te glide dislocations, which strongly supports this assignment of an exciton localised at a dislocation. In the twostep annealing process, the vapor-environment annealing establishes a Cd(Zn)-rich atmosphere.…”

Photoluminescence of CdZnTe thick films obtained by close-spaced vacuum sublimation

“…The PL band at 1.477 eV is due to Y center which corresponds to excitons bound on Te glide dislocations [49][50][51][52]. The nature of this band is supported by the results for CdTe crystal sample obtained from the bottom of the crystal bar where Y band strongly increases [50].…”

Composition dependence of structural and optical properties of Cd1−Zn Te thick films obtained by the close-spaced sublimation

“…In this case, the energy of LO-phonon is about 21 meV. According to [65][66][67][68] the PL band at 1.477 eV is due to Y center which corresponds to excitons bound on Te glide dislocations. Thus, the intensity of the Y band may be used as an indicator of the presence of dislocations in CdTe.…”