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In this work we use analytical and 3D numerical modeling tools to analyze data from InP/In0.53Ga0.47/InP double layer planar 15 pixel pitch focal plane arrays (FPAs) designed to image in the near infrared to determine array suitability for operation under low-level illumination, including overcast, “Night Glow”- only conditions. Notable is that the diffusion dark current component is the dominant current component near and above 300K and is limited by band-to-band radiative recombination processes. The Shockley- Read- Hall (SRH) minority carrier lifetime is τSRH =107μs. Recombination through band gap states in the space charge region (SCR) situated at the intrinsic Fermi level is the dominant component for temperatures below 300K as previously demonstrated using 3-D numerical simulations consisting of both bulk area and perimeter dependent components. 3-D numerical simulations in combination with scanning capacitance microscopy are paramount to characterizing the Zn-diffused p+n shallow step homojunction and to identifying technology limitations in small pitch high density (FPAs). Photon recycling effects, i.e., effects caused by repeated trapping of photons, are not observed in the measurements of the minority carrier lifetime and the diffusion dark current component. As a result, the diffusion current component Jdiffusion α to the radiative recombination rate Gr(α) and the radiative minority carrier lifetime τradiative = 1/BNd, where B is the radiative recombination coefficient and Nd the majority carrier concentration.