ABSTRACT
Investigate influences of growth interruptions on the morphology of GaSb/GaAs quantum wells by transmission electron microscopy. Two samples with five GaSb quantum wells with different thickness were grown by molecular beam epitaxy on GaAs. GaSb/GaAs heterostructures have gained considerable interest in years. Owing to their type II band alignment, this material combination is interesting from a fundamental physics point of view: the holes are confined in the quantum wells, whereas electrons are confined in adjacent barrier layers. The reduced overlap of the electron and hole wave functions results in longer lifetimes of the excitons compared to heterostructures with type I band alignment. Investigations reveal the segregation of Sb in GaSb/GaAs quantum wells with different nominal thickness. The quantum wells of the sample grown without interruption contained a larger amount of GaSb, which most likely can be attributed to desorption of Sb atoms from the floating layer and possibly from the chemisorbed GaSb layer.
