InAs self-assembled quantum dots grown on an InP (311)B substrate by molecular beam epitaxy

Self-assembled InAs quantum dots (QDs) have been grown by solid-source mole cular beam epitaxy on a (311)B InP substrate. Transmission electron microsc opy clearly shows that a high density of smaller InAs islands can be obtain ed by using such a high index substrate. After introducing a lattice-matche d underlying In0.52Al0.24Ga0.24As layer, the InAs QDs are much more uniform in size and form two-dimensional well ordered arrays. The photoluminescenc e (PL) spectra also confirm that the InAs QDs grown on underlying In0.52Al0 .24Ga0.24As have a better quality than those grown in the In0.52Al0.48As ma trix. A simple calculation indicates that the redshift of the PL peak energ y mainly results from InAs QDs on underlying In0.52Al0.24Ga0.24As of large size. (C) 2001 American Institute of Physics.