Interfaces in InAs/GaSb Superlattices Grown by Molecular Beam Epitaxy

Short period InAs(4ML)/GaSb(8ML) superlattices (SLs) with InSb- and mixed-like (or Ga_1-xIn_xAs_1-ySb_y-like) interfaces (IFs) are grown by molecular-beam epitaxy (MBE) on (001) GaSb substrates at optimized growth temperature. Raman scattering reveals that two kinds of IFs can be formed by controlling shutter sequences. X-ray diffraction (XRD) and atomic force microscopy (AFM) demonstrate that SLs with mixed-like IFs are more sensitive to growth temperature than that with InSb-like IFs. The photoluminescence (PL) spectra of SLs with mixed-like IFs show a stronger intensity and narrower line width than with InSb-like IFs. It is concluded that InAs/GaSb SLs with mixed-like IFs have better crystalline and optical properties.