Formation of GaSb/GaAs quantum dots in MOCVD growth

The formation of GaSb quantum dots on a GaAs (001) substrate under metalorganic chemical vapor deposition conditions is investigated. Transmission electron microscopy images and photoluminescence measurements show the island density to be determined in an initial kinetically controlled phase. Subsequently, mass transfer from the two-dimensional wetting layer sustains the growth of the GaSb quantum dots (QDs). Many-particle effects in the type II QDs are investigated by excitation- and temperature-dependent photoluminescence measurements. The peculiar optical behavior is dominated by Coulomb charging and state filling of the localized holes.