PHONONS IN ZNTE CDSE SUPERLATTICES WITH INTERCHANGE OF CATION LAYERS ACROSS INTERFACES/

The ZnTe/CdSe superlattice is one of the wide-gap semiconductor superl attices grown successfully in recent years which have potential applic ations in blue-green diode lasers. There exists experimental evidence of interchange of entire atom layers across the interfaces of ZnTe/CdS e superlattices in spite of the resulting interface strain. First-prin ciples pseudopotential calculations of the total energy of such system s confirmed the possibility of such interchanges. By using the combina tion of a first-principles pseudopotential method and an empirical met hod with parameters extracted from the available experimental data and pseudopotential calculations, we studied phonons in ZnTe/CdSe superla ttices with interchange of atom layers across the interface. The resul ts are compared with phonons in ZnTe/CdSe superlattices with ideal int erfaces. Several unique features of phonon modes in superlattices with interchange of atomic layers across interfaces are identified and dis cussed. These results provide more information about interface structu res in such heterostructures, and we hope that they will stimulate mor e experimental measurements in these materials.