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Highlights • Selection of the d 1 determines the N S , at which detectivity reaches maximum. • d 1opt is higher for equal- than for matched-absorbers detectors. • D* MAX is slightly lower for equal- than for matched-absorbers detectors. • Detectivities are comparable for both type of interband cascade detectors. • Total absorber thickness is higher for the matched-absorbers detector. Abstract The paper presents the performance of the interband cascade type-II superlattice infrared photodetectors. Such photodetectors are made up of multiple stages, which are connected in series using an interband tunneling heterostructure. In this paper, we compare two different architectures of the cascade structure: equal absorber thickness in all stages and varied absorber thickness. In our calculation, in the case of equal absorber throughout the structure, we took into account electrical current gain. The selection of the first absorber thickness d 1 determines the number of possible stages N S , at which detectivity reaches maximum value, which is especially important in case of varied absorbers thickness to meet the quantum efficiency condition (equal quantum efficiency in each stage of the device). Optimal first absorber thickness d 1opt is higher for equal absorbers than for matched-absorbers detectors, but maximum value of detectivity is slightly lower. We compared theoretical results with experimental ones, obtaining good agreement. [ABSTRACT FROM AUTHOR]

This study reports on photoelectrical performance of the long‐wave infrared HgCdTe high operating temperature (200–230 K) detector for the fast response time operating under unbiased conditions. The detailed analysis of the response time as a function of device architecture was conducted pointing out optimal working conditions and structure. The response time of the long‐wave (xCd = 0.19) HgCdTe detector for temperatures reached by thermoelectrical cooling (200–230 K) was estimated at the level of τs < 0.6 ns for unbiased condition while responsivity Ri ∼ 1.8 A/W and detectivity was assessed at the level of D* ∼ 1.6 × 1010 cm Hz1/2 /W. It was shown that extra series resistance Rseries < 10 Ω (resistance–capacitance time constant) plays a decisive role in order to reach τs < 1 ns meaning that device processing is much more important rather than fundamental limitations imposed by physics. [ABSTRACT FROM AUTHOR]