Low density of self-assembled InAs quantum dots grown by solid-source molecular beam epitaxy on InP(001)

The authors report on a postgrowth method to obtain low density InAs∕InP(001) quantum dots by solid-source molecular beam epitaxy. They used an approach based on the ripening of the InAs sticks, which is triggered by the sample cooling under arsenic overpressure, before InP capping. Atomic force microscopy images show the evolution of InAs islands from sticks oriented along the [1-10] direction to dot-shaped islands with a density that can be reduced to about 2×109dots∕cm2. Macro- and microphotoluminescence reveal that these diluted InAs dots exhibit a strong spatial confinement and emit in the 1.55μm range.