Metal-organic chemical vapor deposition of GaSb/GaAs quantum dots: the dependence of the morphology on growth temperature and vapour V/III ratio

GaSb quantum dots have been widely applied in optoelectronic devices due to its unique electrical and optical properties. The effects of metal-organic chemical vapor deposition(MOCVD) parameters, such as growth temperature and vapour V/III ratio[V/III ratio means the molar ratio of trimethylgallium(TMGa) and triethylantimony( TESb)], were systematically investigated to achieve GaSb quantum dots with high quality and high density. The features of surface morphology of uncapped GaSb quantum dots were characterized by atomic force microscope( AFM) images. The results show that the surface morphologies of quantum dots are strongly dependent on growth temperature and vapour V/III ratio. GaSb quantum dots with an average height of 4.94 nm and a density of 2.45×1010 cm–2 were obtained by optimizing growth temperature and V/III ratio.