Growth of self-assembled (Zn)CdSe nanostructures on ZnSe by migration enhanced epitaxy

The growth of CdSe on ZnSe by migration enhanced epitaxy has been studied in situ by means of reflection high-energy electron diffraction (RHEED) and reflection anisotropy spectroscopy (RAS). The change from a streaky to a spotty RHEED pattern during CdSe deposition indicates the transition to a three-dimensional growth mode. This change is accompanied by a damping of RHEED intensity oscillations and a decrease in the overall intensity. RAS spectra show a pronounced change at a photon energy of about 2.2 eV with increasing CdSe thickness. To investigate the role of lattice mismatch, ternary ZnCdSe layers of different compositions have been grown. With decreasing Cd concentration the critical thickness for the growth mode transition increases and for Cd concentrations below 30% no growth mode transition could be observed. (C) All 1999 Elsevier Science B.V. All rights reserved.