Abstract: | We develop a modified two-step method of growing high-density and
narrow size-distribution InAs/GaAs quantum dots (QDs) by molecular
beam epitaxy. In the first step, high-density small InAs QDs are
formed by optimizing the continuous deposition amount. In the second
step, deposition is carried out with a long growth interruption for
every 0.1 InAs monolayer. Atomic force microscope images show that
the high-density ($\sim $5.9$\times $10$^{10}$\,cm$^{ - 2})$ good
size-uniformity InAs QDs are achieved. The strong intensity and
narrow linewidth (27.7\,meV) of the photoluminescence spectrum show
that the QDs grown in this two-step method have a good optical
quality. |