Peculiarities of migration-enhanced-epitaxy (MEE) versus molecular beam epitaxy (MBE) growth kinetics of CdSe fractional monolayers in ZnSe

Peculiarities of migration-enhanced epitaxy of CdSe fractional monolayers i n a ZnSe matrix are studied using photoluminescence (PL) and transmission e lectron microscopy (TEM) techniques. Dependencies of Cd incorporation coeff icient on Se/Cd flux ratio as well as on the temperature are discussed. The critical Cd coverage of growth surface per cycle is established by PL to b e of 0.5 ML at 280 degrees C and depends on substrate temperature. The exce ss of Cd deposited is suggested to accumulate in CdSe-based nanoscale islan ds (similar to 30 nm in diameter) formed at sites of the growth surface imp erfections like point and extended defects, which is confirmed by plan-view TEM measurements. (C) 1999 Elsevier Science B.V. All rights reserved.