High operating temperature InAsSb-based mid-infrared focal plane array with a band-aligned compound barrier

Abstract

In this work, by utilizing a band-aligned AlAs0.08Sb0.92/AlSb-based unipolar compound barrier design, a high-operability (∼99.7%) InAsSb bulk absorber-based mid-wavelength infrared 640 × 512 focal plane array (with a 50% cut-off wavelength at 4.1 μm at 150 K) exhibiting distinct infrared images from 150 K up to 205 K has been achieved, which suggests great potential for high operation temperature detection applications. At 150 K and −400 mV bias, the photodetectors exhibit a low dark current density of ∼3.9 × 10−6 A∕cm2, a quantum efficiency of 65.1% at peak responsivity (∼3.8 μm), and a specific detectivity of 1.73 × 1012 Jones. From 150 to 185 K, the focal plane array exhibits ∼30.2 mK and ∼69.5 mK noise equivalent temperature difference values by using f/2.0 optics and 6.45 ms and 0.61 ms integration times, respectively.