ATOMIC REARRANGEMENT AT ZNTE CDSE INTERFACES

X-ray-absorption fine-structure spectroscopy and x-ray diffraction hav e been used to study the local atomic structure of four different shor t-period ZnTe/CdSe (001) superlattices grown by molecular-beam epitaxy . The data indicate Zn-Se and Cd-Te coordination numbers greater than those expected for sharp interfaces in the superlattice. Although stra in would appear to suppress interdiffusion,it is shown that the result s are consistent with an interchange of the Zn and Cd atomic planes ac ross the Zn-Se interface and Se and Te atomic planes across the Cd-Te interface. Theoretically, this switch of atomic planes has been shown to be energetically favorable by comparing the changes in chemical bon d-formation energies and strain energies between a perfect superlattic e and one with the above-mentioned switching of atomic planes. Accommo dation of this strain is shown through bond bending and bond stretchin g at the newly formed interfaces.