COMPARISON OF THE ELECTRONIC-STRUCTURE OF INAS GAAS PYRAMIDAL QUANTUMDOTS WITH DIFFERENT FACET ORIENTATIONS/

Using a pseudopotential plane-wave approach, we have calculated the el ectronic structure of strained InAs pyramidal quantum dots embedded in a GaAs matrix, for a few height (h)-to-base(b) ratios, corresponding to different facet orientations {101}, {113}, and {105}. We find that the dot shape (not just size) has a significant effect on its electron ic structure. In particular, while the binding energies of the ground electron and hole states increase with the pyramid volumes (b(2)h), th e splitting of the p-like conduction states increases with facet orien tation (h/b), and the p-to-s splitting of the conduction states decrea ses as the base size (b) increases. We also find that there are up to six bound electron states (12 counting the spin), and that all degener acies other than spin, are removed. This is in accord with the conclus ion of electron-addition capacitance data, but in contrast with simple k.p calculations, which predict only a single electron level. [S0163- 1829(98)50516-4].