STUDY OF RECONSTRUCTION AT INTERFACES OF CDSE ZNTE SUPERLATTICES BY TOTAL-ENERGY CALCULATIONS/

ZnTe/CdSe superlattices are II-VI heterostructures with a lattice mism atch less than 0.3%, so strain effects are expected to be negligible f or ideal structures except for the two interface layers that consist o f ZnSe and CdTe. Recent experiments indicated the exchange of whole at omic layers across the interfaces in ZnTe/CdSe superlattices despite t he fact that more atomic layers near the interface would become strain ed. To understand such exchanges, first-principles pseudopotential stu dies of several different interface structures were performed. Total e nergies, band offsets, and band structures of superlattices with diffe rent atomic rearrangements at interfaces are studied and compared. Our results indicate that the exchange of cation atomic layers across an anion atomic layer in these superlattices is energetically favorable. (C) 1995 American Vacuum Society.