Growth and characterization of short-period InAs/GaSb superlattice photoconductors

Abstract

The short-and mid-wavelength infrared detectors based on short period type II superlattices (SLs) InAs (2ML) / GaSb (8ML) and InAs (8ML) / GaSb (8ML) were grown by molecular-beam epitaxy on semi-insulating GaAs substrates. An interfacial misfit mode AlSb quantum dot layer and a thick GaSb layer were grown as buffer layers. Room-temperature optical transmittance spectra showed clear absorption edge at ~2µm and ~5µm. The 50% cutoff wavelength of the two photoconductors was 2.1µm and 5.05µm in photoresponse at 77K respectively. The blackbody detectivity was beyond 2×10 8 cmHz 1/2 /W at 77K and 1×10 8 cmHz 1/2 /W at room temperature with 8 V/cm bias.

Study of Mesa Etching for Infrared Detector Based on InAs/GaSb Superlattice

“…The samples were GaSb (001), InAs (001) bulk materials and InAs (8ML) /GaSb (8ML) superlattice grown on GaSb substrates by molecular beam epitaxy method [7]. The thickness of superlattice was 320 periods about 1.8 µm.…”