A Thermoelectrically Cooled nBn Type‐II Superlattices InAs/InAsSb/B‐AlAsSb Mid‐Wave Infrared Detector

Abstract

Herein, an nBn barrier mid‐wave infrared InAs/InAsSb (xSb = 0.4) type‐II superlattice (T2SL) detector operating in the thermoelectrical (TE) cooling condition is reported. AlAsSb (Sb‐composition, xSb ≥ 0.975) is shown not to introduce an additional barrier in the valence band in the analyzed temperature range (≥200 K) reached by four‐stage TE cooling in nBn barrier architectures with a T2SL InAs/InAsSb active layer. The dark current and photocurrent produced are analyzed in relation to the barrier and contact layer doping, with the Sb composition of the barrier indicating the optimal architecture. The results of the simulation are compared with the experimental results of the HgCdTe and InAsSb nBn barrier detectors. A detectivity of ≈1010 cmHz1/2 W−1 at 200 K is reported without an immersion lens (≈1011 cmHz1/2 W−1 is reported for an immersed detector).

Antimonide-based high operating temperature infrared photodetectors and focal plane arrays: a review and outlook

“…Various IR detector architectures have been explored and applied for HOT conditions, such as nBn [32,34,35,38,[124][125][126], pBn [33], double barrier [15], interband cascade [107], p-i-n [36], and optically immersed photoconductors [127]. Most of them concentrated on barrier infrared detector (BIRD) structures, especially for nBn barrier MWIR and LWIR PDs, accompanied by both theoretical [128][129][130] and experimental results [15, 32-35, 38, 124-126], indicating that the use of a wide-bandgap barrier would inhibit a device's dark current density and consequently improve its specific detectivity. With regard to temperature dependence, the Auger recombination would act as a major contributing factor to the minority lifetime at high operation temperatures [125,131].…”

Emerging Type‐II Superlattices of InAs/InAsSb and InAs/GaSb for Mid‐Wavelength Infrared Photodetectors

“…Moreover, employing barrier architectures facilities easy implementation of the passivation processes to minimize surface leakage current. [14] This has resulted in significant improvements in the overall T2SL photodetector's performance with the demonstration of HOT of 150 K [162] and beyond 190 K [203,204] in the MWIR region. This could potentially eliminate the need for cryogenic cooling leading to reduced cost, increased portability, and reduction in size, weight, and power consumption (SWaP) of PDs making them suitable for use in IR space applications.…”

Admittance of MIS Structures Based on nBn Systems of Epitaxial HgCdTe for Detection in the 3–5 μm Spectral Range

“…The use of unipolar barrier architectures (e.g., in the nBn configuration [1]) makes it possible to increase the operating temperature of infrared detectors based on III-V semiconductor compounds [2,3] by suppressing some components of the dark current (generation current in depleted regions, surface leakage current). The development of nBn detectors based on HgCdTe grown by molecular beam epitaxy (MBE) is of interest because of the significant technological advantages over popular matrix photodiodes based on MBE HgCdTe, in which p-n junctions are usually created using a defect-forming ion implantation procedure [4].…”