Cathodoluminescence microscopy of doped GaSb crystals

Abstract

We present the homogeneity and luminescence properties of bulk GaSb obtained by the cathodoluminescence (CL) technique in the scanning electron microscope. The samples used in this study are as-grown undoped and impurity diffused (tellurium) and doped (chromium) material. CL investigations have revealed a non uniform distribution of native defects in GaSb wafers. Post growth annealing in vacuum, gallium or antimony atmospheres causes an increase in homogeneity in CL images. Te diffusion and Cr doping provides new information about defects in GaSb. CL images and CL spectra recorded in these samples support that the type of defects formed is a function of diffusion time and impurity concentration.