Multilayer GaSb/GaAs self-assembled quantum dots grown by metalorganic chemical vapor deposition

A mutilayer structure of self-assembled GaSb/GaAs quantum dots (QDs) has been grown for the first time by metalorganic chemical vapor deposition (MOCVD) in the Stranski-Krastanow (S-K) growth mode. Evidence of the growth of the self-assembled quantum dots was provided using transmission electron microscopy. This study shows that the GaSb/GaAs heterostructure is well controlled and there is no sign of the intermixing that often occurs for this system. The existence of the quantum dots and of a wetting layer was also supported by photoluminescence spectra. These results open the way to the realization of GaSb/GaAs QD superlattice structures in which the islands have equal size in all layers. The QD structures also provide an opportunity for studying electronic coupling between islands.