Assessment of InGaSb crystals by cathodo-luminescence microscopy and spectroscopy

Abstract

Low band-gap InGaSb crystals are of interest for the development of thermo-photo-voltaic (TPV) cells and other devices operating in the infrared spectral range. In this work, cathodoluminescence (CL) in the scanning electron microscope (SEM) has been applied to study the homogeneity of InGaSb material grown by the vertical Bridgman technique with regard to effective incorporation of In to the ternary alloy and the nature and distribution of defects influencing the luminescence properties of this semiconductor. Back-scattered electron imaging and wavelength dispersive X-ray mapping were used as complementary techniques to CL for analysis of chemical composition and element distribution. The results show that local CL spectra provide information on the effective formation of the alloy, not revealed by other techniques.