Performance of Hg_1−xCdxTe infrared focal plane array at elevated temperature

Abstract

The simulated optical and electrical performance of the infrared HgCdTe focal plane array (FPA) for elevated operation temperature is reported. The depleted absorber layer is explored for equilibrium mode of operation up to 160 K. A resonant cavity is created to improve photon-matter interaction and hence, reduces the required absorption volume. The volume of the active region of HgCdTe detector is reduced by 70% in this manner. Dark current density is decreased without compromising the quantum efficiency. The effect of the reduced band filling effect leading to higher absorption coefficient and more efficient utilization of incident flux is employed. High quantum efficiency is achieved in a thin compositionally graded n + /ν/π/p HgCdTe photo-diode. This architecture helps to minimize the requirement of charge handling capacity in the CMOS read-out integrated circuit (ROIC) as the operation temperature is increased. Quantum efficiency ∼30% or above is shown to be sufficient for Noise Equivalent Temperature Difference (NETD) less than 20 mK with the reported design.

Electrical profiling of arsenic-implanted HgCdTe films performed with discrete mobility spectrum analysis

“…Among the materials used for the fabrication of photo-electronic devices, HgCdTe (MCT), the basic material for photodetectors operating in the long-and middle-wavelength parts of the infrared (IR) range, stands out due to its unique properties [1,2]. Modern MCT-based IR imaging applications have a demand for high photodetector operating temperature, which, among other benefits, reduces power consumption and the size and weight of systems while also increasing their lifespan [3,4]. Current MCT growth technology fabricates n-type materials with concentration of deep centres much lower than that achievable for p-type MCT.…”