Multilayered type-II GaSb/GaAs self-assembled quantum dot structure with image light emission at room temperature

We have investigated the growth of multilayered type-II GaSb/GaAs self-assembled quantum dot (QD) structure. We show that the key point for the growth of the multilayed GaSb/GaAs QDs lies in how to switch the V elements: Sb and As. It is found that, after the dot deposition, a short exposure to As atmosphere smoothes out the GaSb 3D islands and transforms the structure into 2D-like while the 3D islands remain in an Sb soak. There is a large PL energy separation of 214 meV between the QDs and the corresponding 2D-like structure due to the smoothing-out effect. The PL peak of the multilayered dots is at View the MathML source at room temperature (RT) and only digresses from View the MathML source insignificantly for a broad range of temperature from 13 K to RT.