Growth of self-organized GaSb islands on a GaAs surface by molecular beam epitaxy

We systematically investigated the growth of self-organized GaSb islands on a GaAs surface by molecular beam epitaxy technique. The lattice mismatch between GaAs and GaSb is 7.8%. At low growth temperature, only one kind of island can be observed, which is thought to be issued from the nucleation cluster. When the growth temperature is increased, another kind of island appears due to coalescence. When the growth temperature is above 535 °C, only the latter can be observed. From the temperature dependence of island density and size, surface diffusion energy and activation energy of GaSb on a GaAs surface have been determined to be 0.85 and 2.15 eV, respectively.