InSb quantum dots in an InAsSb matrix grown by molecular beam epitaxy

We report on molecular beam epitaxy of InSb insertions in InAs and InAsSb matrices, emitting at wavelengths beyond 4 μm. Different growth techniques for deposition of InSb quantum dots in the 1-2 monolayer range of the InSb nominal thickness, namely conventional molecular beam epitaxy and migration enhanced epitaxy, as well as different matrices (InAs and InAsSb) have been employed for increasing the emission wavelength of the InSb/InAs nanostructures. The formation of InSb quantum dots has been studied in situ using reflection high energy electron diffraction and ex situ by using transmission electron microscopy. The peculiarities of In(Ga)AsSb alloys growth and compositional control are also discussed. Bright photoluminescence up to 4.5 μm has been observed at 80 K. (author)