  This work investigates midwave infrared Type-II InAs/GaSb superlattice (SL)
grown by molecular beam epitaxy on GaSb substrate. In order to compensate the
natural tensile strain of the InAs layers, two different shutter sequences have
been explored during the growth. The first one consists of growing an
intentional InSb layer at both interfaces (namely GaSb-on-InAs and InAs-on-GaSb
interfaces) by migration enhanced epitaxy while the second uses the
antimony-for-arsenic exchange to promote an InSb-like interface at the
GaSb-on-InAs interface. SLs obtained via both methods are compared in terms of
structural, morphological and optical properties by means of high-resolution
x-ray diffraction, atomic force microscopy and photoluminescence spectroscopy.
By using the second method, we obtained a nearly strain-compensated SL on GaSb
with a full width at half maximum of 56 arcsec for the first-order SL satellite
peak. Relatively smooth surface has been achieved with a root mean square value
of about 0.19 nm on a 2 $\mu m$ x 2 $\mu m$ scan area. Finally, a p-i-n device
structure having a cut-off wavelength of 5.15 $\mu m$ at 77K has been
demonstrated with a dark-current level of $8.3 * 10^{-8} A/cm^2$ at -50 mV and
a residual carrier concentration of $9.7 * 10^{14} cm^{-3}$, comparable to the
state-of-the-art.
