Multispectral capability across infrared (IR) bands is a central requirement for third generation, large format IR focal plane array (FPA) detectors. The outstanding properties of HgCdTe allow to fabricate large format, dual-band or two-color IR FPA detectors. In one the of simplest schemes, each pixel includes two stacked p-n absorbers, i.e., two back-to-back p-n photodiodes with different cut-off wavelengths, separated by a thin, wide bandgap layer acting as barrier, and a single bias contact [1-3]. Employing combined electrical (drift-diffusion) and electromagnetic (full-wave, Finite Difference Time Domain) simulations, we investigated a dual-band MWIR-LWIR detector operating at T = 230K, considering a 5 x 5 miniarray of pixels illuminated by a narrow Gaussian beam focused on its central pixel , obtaining useful indications about the optimal bias point and the effects of pixel geometry on the spectral quantum efficiency and inter-pixel crosstalk [4].
(a) The simulated dual-band 5 × 5 MWIR-LWIR miniarray, with the central pixel (CP) and the nearest neighboring pixels (NNs). (b) Simulated spectral QE for Gaussian beam illumination on the CP, and (c) inter-pixel crosstalk.
Further details will be given during the NUSOD-20 Conference.
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P. Martyniuk, et al., “New concepts in infrared photodetector designs,” Appl. Phys. Rev., vol. 1, p. 041102, 2014.
D. Eich, et al., “MCT-based high performance bispectral detectors by AIM,” J. Electron. Mater., vol. 48, no. 10, pp. 6074–6083, 2019.
M. Vallone, et al., “Diffusive-probabilistic model for inter-pixel crosstalk in HgCdTe focal plane arrays,” IEEE J. Electron Devices Soc., vol. 6, no. 1, pp. 664–673, 2018.
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