The luminescence spectroscopy of charge tunable self-assembled InAs quantum dots is reviewed. We discuss that for confined excitons charged with more than three electrons in excess the quantum dot state can be resonantly coupled to the two-dimensional continuum of electronic states of the wetting layer. This coupling manifests itself in a magnetic field and is triggered by photon emission. In contrast the neutral, singly and doubly charged exciton have optical spectra consistent with the artificial atom picture.

9 páginas, 6 figuras.-- PACS: 73.21.La; 75.75.+a.-- Proceedings of the 13th International Winterschool on New Developments in Solid State Physics - Low-Dimensional Systems.

This work was funded by the DFG SFB 348, EPSRC and The Royal Society.

Peer reviewed