Long-wave infrared nBn photodetectors based on InAs/lnAsSb type-ll superlattices

摘要

Long-wave infrared InAs/InAsSb type-II superlattice nBn photodetectors are demonstrated on GaSb substrates. The typical device consists of a 2.2 μm thick absorber layer and has a 50% cutoff wavelength of 13.2 μm, a measured dark current density of 5 × 10~(-4) A/cm~2 at 77 K under a bias of -0.3 V, a peak responsivity of 0.24 A/W at 12 μm, and a maximum resistance-area product of 300 Ω cm~2 at 77 K. The calculated generation-recombination noise limited specific detectivity (D~*) and experimentally measured D~* at 12μm and 77 K are 1 × 10~(10)cm Hz~(1/2)/W and 1 × 10~8cm Hz~(1/2)/W, respectively.