In this Letter, the thermal stability of GaInAsSb grown by molecular-beam epitaxy was investigated. We found a strong blueshift for both bulk material and multiple-quantum-well (MQW) structures caused by thermal annealing. The shift is almost independent of design parameters such as indium concentration, strain, and growth parameters such as temperature. For a 500-nm-thick GaInAsSb bulk layer, a blueshift of 83meV was found after annealing for 2h at 520°C, whereas for MQW structures the maximum shift was 61meV.

In this letter, the authors present the formation of InAs quantum dots on GaInAs and AlInAs lattice matched on InP (001) substrates via molecular beam epitaxy by inserting a two monolayer GaSb sublayer below the InAs quantum dot material. They show that the formation of quantum dots is favored on indium-free and antimony-rich surfaces while quantum dashes are preferentially formed on indium-rich and antimony-free surfaces. Using a thin layer of GaSb between the InAs quantum dot material and the AlInAs or GaInAs matrix, single quantum dots were formed even with low quantum dot densities (≈1∕μm2). These quantum dots give rise to photoluminescence between 1100 and 1500nm depending on the matrix material.