Abstract
InSb quantum dots (QDs) have been grown by molecular-beam epitaxy (MBE) on GaSb substrates. Typical MBE growth conditions lead to a low density (109 cm-2) of large islands which are dislocated. Insertion of a thin InAs nucleation layer increases the QDs density by one order of magnitude which is interpreted in terms of differing In-to-group-V binding energies. Finally, we show that a high density (7 x 1010 cm-2) of small coherent QDs can be grown by using a two-steps procedure. Photoluminescence near 3.5 µm is demonstrated.