Low-Density InAs Quantum Dots Grown on InP(001) Using Solid-Source Molecular Beam Epitaxy with a Post-Growth Annealing Process

Low-density InAs quantum dots (QDs) with a large lateral size were grown on InP(001) by solid-source molecular beam epitaxy with a post-growth annealing process. A decrease in QD density with the amount of InAs deposited was shown by atomic force microscopy, and a density of 5×10 8 QDs/cm 2 was obtained for 0.8 monolayer InAs deposition. Moreover, we found that the growth mechanism of QDs changed significantly depending on the amount of InAs deposited in the vicinity of critical thickness, even if the same annealing condition was applied. Near-field photoluminescence spectroscopy of single QDs demonstrated the high optical qualities of low-density QDs.