Atomic resolution of interface diffusing in short-period InAs/GaSb superlattice

High-angle annular dark-field (HAADF) and electron energy loss spectroscopy in a Cs-corrected scanning transmission electron microscope were utilized for characterizing the interfacial chemical structure of the short-period InAs/GaSb superlattices with atomic resolution. The interfacial features determined from HAADF image contrasts and elemental composition profiles demonstrated that each interface width remains below 4.8 monolayers for all elements, while InAs-on-GaSb interfaces are sharper than GaSb-on-InAs interfaces. Tensile mapping revealed that the In and Sb diffusion at the interface may influence more than the other two elements and modulate the realistic lattice in the sublayers.