Optical properties of strained antimonide-based heterostructures

Abstract

The optical properties of strained GaAsSb/GaAs quantum wells grown by molecular beam epitaxy were investigated by photoluminescence spectroscopy as a function of excitation intensity and temperature. Photoluminescence spectra exhibit strong blue shifts of the emission peak with increasing excitation intensity, ascribed to the interplay between band tail filling at low carrier densities and electrostatic band bending at high carrier concentrations. Spectroscopic data are consistent with a type II band alignment, with a small conduction band offset (ΔEc∼100 meV), and gain spectra are blue shifted with respect to the low excitation luminescence. The large material gain and fast carrier recombination lifetimes demonstrate the viability of this material system for the fabrication of 1.3 μm lasers.