Interfacial chemistry in a ZnTe/CdSe superlattice studied by atom probe tomography and transmission electron microscopy strain measurements

The atomic scale analysis of a ZnTe/CdSe superlattice grown by molecular beam epitaxy is reported using atom probe tomography and strain measurements from high-resolution scanning transmission electron microscopy images. CdTe interfaces were grown by atomic layer epitaxy to prevent the spontaneous formation of ZnSe bonds. Both interfaces between ZnTe and CdSe are composed of alloyed layers of ZnSe. Pure CdTe interfaces are not observed and Zn atoms are also visible in the CdSe layers. This information is critical to design superlattices with the expected optoelectronic properties.