Mid-infrared electroluminescence from coupled quantum dots and wells

The room temperature electroluminescence (EL) between 1.7-2.6 μ from coupled quantum dots and quantum wells in the InAs/InSb/GaSb materials system was investigated. The samples which were investigated consisted of a single narrow InAs quantum well grown below a layer of InSb quantum dots in a GaSb matrix. It was found that the thickness of the GaSb space layer lowers the energy from that of a quantum well alone. The results reveal the occurrence of a sharp transition after a single monolayer coverage of GaSb either due to structural changes in the quantum dots or from the shrinkage of the quantum well.