Formation of self-assembled quantum dots on AlInAs and GaInAs matrices using a GaSb sublayer

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.