Short-wavelength interband cascade infrared photodetectors operating above room temperature

Abstract

High temperature operation (250–340 K) of short-wavelength interband cascade infrared photodetectors (ICIPs) with InAs/GaSb/Al0.2In0.8Sb/GaSb superlattice absorbers has been demonstrated with a 50% cutoff wavelength of 2.9 μm at 300 K. Two ICIP structures, one with two and the other with three stages, were designed and grown to explore this multiple-stage architecture. At λ = 2.1 μm, the two- and three-stage ICIPs had Johnson-noise-limited detectivities of 5.1 × 109 and 5.8 × 109 cm Hz1/2/W, respectively, at 300 K. The better device performance of the three-stage ICIP over the two-stage ICIP confirmed the advantage of more stages for this cascade architecture. An Arrhenius activation energy of 450 meV is extracted for the bulk resistance-area product, which indicates the dominance of the diffusion current at these high temperatures.