Comparison of the bandgaps of Ga-containing and Ga-free type II superlattices via photoluminescence measurements.

A 532 nm laser was used to obtain the photoluminescence spectra of GaSb/InAs and InAs/InAsSb type II superlattices at 5 K using a variety of power settings (10mW-2W). The main goal of these measurements was to obtain the bandgap of each investigated sample. The data was fit with a Gaussian/Voigt function. The maximum of the fitted curve corresponded to the bandgap of the sample. The bandgap energies of thee Ga-containing and Ga-free superlattices were then compared. Preliminary data suggests that while bandgap ranges were broader for Ga-free samples, indicating more defects, Ga-free materials are viable alternatives to Ga-containing materials for optical applications based on the intensity and consistency of their photo-response.