A remarkable change in topology occurs when InyGa1−yAs 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.

We gratefully acknowledge financial support by the Deutsche Forschungsgemeinschaft through the ‘Sonderforschungsbereich 348’ and the ‘Schwerpunktprogramm Benetzung und Strukturbildung an Grenzflächen’

5 páginas, 5 figuras.

Peer reviewed