Enhanced mid-wavelength infrared focal plane arrays based on photon-trapping in InAs/ InAsSb strained layer superlattices

Infrared detectors performance is often limited by high dark currents and restricted operational temperatures. This study employs femtosecond laser-induced nanostructures on GaSb substrates within InAsSb focal plane arrays (FPAs) to enhance performance. These structures are optimized to maximize infrared light absorption. The enhanced FPAs demonstrate significant performance improvements, achieving quantum efficiencies of up to 42.7 % and reducing the noise-equivalent temperature difference (NETD) to as low as 15.6 mK. The dark current density is 5.7 × 10⁻⁶A/cm² and a high peak detectivity up to 1.34 × 10¹² cm Hz^1/2/W is realized at an operational temperature of 120 K. These advancements enhance durability and thermal stability, making the detectors adaptable to diverse environmental conditions.