Morphological transformation of In yGa 1− yAs islands, fabricated by Stranski–Krastanov growth

Abstract

A remarkable change in topology occurs when In y Ga 1− y As quantum dots, grown by Stranski–Krastanov self-organization, are covered by a thin layer of GaAs. The nano-islands rearrange themselves to form volcano-like islands with distinct, ring-like features. The island topology can be preserved during overgrowth and thus used for the fabrication of ring-shaped quantum structures. The experimental data suggests that two mechanisms, diffusion and dewetting, are driving the transformation from dots to rings.