Effects of segregation on the optical properties of (In,Ga)As/GaAs quantum wells grown by MBE under various conditions

Thermally detected optical absorption measurements have been performed at liquid helium temperature in order to study the effects of In segregation on the optical properties of InxGa1-xAs/GaAs quantum wells grown by molecular-beam epitaxy under various growth conditions. The experimental data are analysed using a kinetic model explicitly including the growth parameters. The variation of the In surface segregation with substrate temperature and growth rate is investigated. This work demonstrates that a way to limit segregation is to prevent the system from reaching thermodynamic equilibrium by choosing low growth temperatures or high growth rates. It is shown, however, that growth temperature is the most efficient parameter to kinetically limit the exchange process. (C) 1997 Elsevier Science S.A.