Self organized grown Stranski-Krastanow II-VI quantum dots vs. colloidal nanocrystals integrated in epitaxial nanostructures

摘要

We have integrated colloidal CdSe nanocrystals (NC) in MBE-grown ZnSe layers. In this paper we compare their density, size, size distribution and their optical tuning range with that of self-organized grown Stranski-Krastanow (SK) CdSe-QDs which are used as a reference. We find that the density of epitaxially overgrown NCs can be varied in a wider range than the SK-QD density. The size and shape of NCs is variable and this leads to a wide optical tuning range of the NC emission. The size of SK-QD is fixed due to the thermodynamic formation process. Further we found, that the size distribution of overgrown NCs is in the range of the size distribution of SK-QDs or even smaller.