VIRTUAL-SURFACTANT EPITAXY OF INAS QUANTUM-WELLS

We study the solid-source MBE growth of InAs films embedded in Al0.48In0.52As lattice matched to InP. Under As-stable conditions, the high strain of the InAs film induces a morphological phase transition from layer-by-layer to island nucleation. In contrast, during MBE growth without direct AS4 flux, islanding is inhibited. The In-stabilized surface imposes kinetic limitations to the migration of adatoms and forces layer-by-layer nucleation, thus acting as a virtual surfactant. This technique produces samples of superior structural and optical quality exhibiting high luminescence efficiency up to room temperature.