High-density, uniform InSb∕GaSb quantum dots emitting in the midinfrared region

The authors have developed a multistep molecular-beam epitaxy growth technique which allows them to grow InSb quantum dots with high structural perfection and high density. This technique consists in the deposition at a very low temperature followed by a properly designed annealing step. Fully strained InSb∕GaSb quantum dots with a density exceeding 7×1010cm−2 and lateral sizes in the 20–30nm range have been obtained. Narrow photoluminescence emission is obtained around 3.5μm up to room temperature.