Long Wavelength Infrared InAs/GaSb Superlattice Photodetectors With InSb-Like and Mixed Interfaces

We report on long wavelength infrared photodetectors using InAs/GaSb superlattices (SLs) with InSb-like and mixed interfaces (IFs). X-ray diffraction (XRD) measurements indicate that the SLs with mixed IFs have a narrower linewidth. The full-width at half-maximum of the XRD satellite peak is 24 arcsec for the sample with InSb-like IFs and is only 17 arcsec for the sample with mixed IFs. However, in terms of infrared photodetection, InSb-like IFs are superior to the mixed ones. Stronger photoluminescence and photoresponse signals are observed for the sample with InSb-like IFs.