Frank dislocation loops in HgTe∕CdTe superlattices on CdTe∕Si(211)B substrates

Abstract

The defect structures in HgTe∕CdTe superlattices (SLs) on CdTe∕Si(211)B substrates grown by molecular-beam epitaxy have been investigated using (scanning) transmission electron microscopy and electron energy loss spectroscopy. Straight Hg-rich defects perpendicular to the SLs have been observed near the substrate while Frank dislocation loops (FDLs) are seen far from the substrate. The Hg-rich defects exhibit only a compositional variation with no significant atomic shift, and can be considered to be a remnant of a FDL which has climbed by thermal diffusion during the growth.