Growth and Charaterization of Short Period InAs/GaSb Superlattices Photoconductors

摘要

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.