Influence of As-stabilized surface on the formation of InAs∕GaAs quantum dots

In this article, we report the growth of InAs∕GaAs quantum dots (QDs) grown under different As4-supply procedures. The growth of the investigated samples carried out by the three procedures of As shutter always opened, As shutter initially opened, and As shutter initially closed. The samples grown by the former two approaches show a uniform QD distribution and the multiple-peak luminescence, which correspond to ground-state, first-excited-state, and second-excited-state luminescence, while that grown by the latter only shows large InAs islands. The results suggest that the As-stabilized condition at the initial stage of QD growth is very critical for the high-quality QD formation.