High operating temperature mid-wavelength infrared InAsSb nBn detectors and focal plane array

Raising the operating temperature of mid-wavelength infrared detectors is critical for meeting the low size, weight, and power (SWaP) demands of infrared imaging systems. In this work, we report and analyze a high operating temperature (HOT) InAs_0.91Sb_0.09 nBn mid-wave infrared (MWIR) focal plane array (FPA) and single element photodetectors with AlAs/AlSb superlattices as the electron barrier. Under an applied bias of -350 mV, the nBn photodetectors demonstrate a dark current density of 2.42 × 10^-6 A/cm² and a quantum efficiency of 60.5%, resulting in a specific detectivity of 1.94 × 10¹²cm·Hz^1/2/W at 150 K. At 300 K, the photodetectors exhibit a dark current density of 5.54 × 10^-2 A/cm² and a specific detectivity of 1.52 × 10¹⁰cm·Hz^1/2/W. The 15-µm pitch 640 × 512 FPA achieves a high operativity of 99.5% and exhibits a noise equivalent temperature difference (NETD) value of 37.9 mK using f/1.6 optics at 150 K. The InAsSb MWIR FPA device operates at temperatures up to 230 K, offering promising potential for applications requiring reductions in SWaP.