HgCdTe Detectors Under Non-Equilibrium Conditions for High Operating Temperatures

High sensitivity HgCdTe focal plane arrays operating at 77 K can be tailored for response across the infrared spectrum. However, the cooling systems required to achieve the desired sensitivity makes them heavy and therefore unsuitable for the next generation of interceptor seekers. Reducing cooling requirements will allow the detector’s integration in lighter and more compact systems. Superior operating temperatures can be reached with the employment of HgCdTe infrared detectors operating under non-equilibrium conditions. The concept is to suppress Auger recombination and the corresponding dark current in specially designed detector structures. The dark current is reduced by several orders of magnitude, along with dramatic increases in recombination lifetimes, dynamic impedances and detectivities. We propose to design and develop a high operating temperature (HOT) infrared array technology based on HgCdTe grown by molecular beam epitaxy. In Phase I, we successfully demonstrated long wavelength infrared HgCdTe HOT single element photodiodes. The efforts will be extended to 320x256 mid- and long wavelength infrared focal plane arrays in Phase II. The proposed technology provides sensitive operation at high operating temperatures, is compatible with multi-band response and large format technology, and therefore meets next generation MDA infrared seeker technology requirements.