Mid-wavelength infrared InAs/GaSb type Ⅱ superlattice detectors

Infrared (IR) photo detectors based on InAs/GaSb type II superlattice have developed quickly in recent years. Many groups show great interest in InAs/GaSb superlattice detector for its superiors as high quantum efficient, high working temperature, high uniformity and low dark current densities. The growth of mid-wavelength infrared InAs/GaSb superlattice on GaSb substrates by molecular beam epitaxy (MBE) was studied. The growth temperature and the interface structures to obtain high quality material were optimized. The InAs/GaSb superlattice layers were characterized by atomic force microscope(AFM) and high resolution X-ray diffraction(XRD). Finally, highly lattice matched mid-infrared InAs/GaSb superlattice material was achieved. The FWHM of the 0th satellite peak of X-ray scanning curve is 28.8 arcsec. The p-i-n single IR photodiode based on InAs/GaSb superlattice has current responsivity of 0.48 A/W and blackbody detectivity of 4.541010 cmHz1/2W, and peak detectivity of 1.751011 cmHz1/2W at 77 K.