GaAs in GaSb: a new type of heterostructure emitting at 2 μm wavelength

We report growth as well as optical and structural studies of a new type of a GaAs/GaSb heterostructure, with 1–3 monolayer thick GaAs layers embedded within unstrained GaSb. In such structures the GaAs layer is under tensile stress, in contrast to the situation in which self-organized growth of quantum dots is commonly observed. The structure emits light in the 2 μm wavelength range. The emission characteristics are explained by a combination of quantum confinement effects and localization on nanoscale potential fluctuations.