Highly selective two-color mid-wave and long-wave infrared detector hybrid based on Type-II superlattices

Abstract

We report a two-color mid-wave infrared (MWIR) and long-wave infrared (LWIR) co-located detector with 3 μm active region thickness per channel that is highly selective and can perform under high operating temperatures for the MWIR band. Under back-side illumination, a temperature evolution study of the MWIR detector's electro-optical performance found the 300 K background-limit with 2π field-of-view to be achieved below operating temperatures of 160 K, at which the temperature's 50% cutoff wavelength was 5.2 μm. The measured current reached the system limit of 0.1 pA at 110 K for 30 μm pixel-sized diodes. At 77 K, where the LWIR channel operated with a 50% cutoff wavelength at 11.2 μm, an LWIR selectivity of ~17% was achieved in the MWIR wave band between 3 and 4.7 μm, making the detector highly selective.

Thermal conductivity tensors of the cladding and active layers of antimonide infrared lasers and detectors

“…III-V antimonide infrared (IR) detectors typically operate cryogenically [1,2], whereas the latest generation of midwave IR (mid-IR) lasers operates at room temperature [3,4]. However, both performances degrade rapidly with increasing temperature.…”

“…A closely-related antimonide heterostructure is the InAs/GaSb type-II superlattice (T2SL) that has been used successfully to suppress dark currents and improve the detectivities of mid-IR and long-wavelength (LWIR) photodiodes (PDs) [1]. However, because the dark currents of mid-IR and LWIR PDs and detectors can increase by several orders of magnitude with temperature [2], it is important to calibrate the thermal conductivities of the active and barrier layers. For example, an InAs/GaSb T2SL with 39.6/21.3Å is used for the active region of an LWIR PD with 50% cut-off around 11 µm.…”

Effects of layer thickness and alloy composition on carrier lifetimes in mid-wave infrared InAs/InAsSb superlattices

“…The InAs/Ga(In)Sb type-2 superlattice (T2SL) has been a popular material system in recent years for infrared (IR) optoelectronic devices operating in the mid-wave (MWIR) and long-wave (LWIR) infrared bands. [1][2][3][4] As a T2SL, they have potential advantages over bulk HgCdTe IR photodetectors, such as the ability to tune the bandgap energy by controlling the layer thicknesses as well as alloy composition, band engineered lower Auger recombination rates, 5 more favorable effective masses, lower fabrication cost, and lower predicted dark currents. 6 Single element detectors show high sensitivity at 80 K operating temperatures; 7 however, they underperform compared to bulk HgCdTe due to significantly shorter minority carrier lifetimes, which limits the performance of the InAs/Ga(In)Sb T2SL detectors.…”

High performance bias-selectable dual-band short-/mid-wavelength infrared photodetectors based on type-II InAs/GaSb/AlSb superlattices

“…Based on the stability and robustness of the mature III-V compound technology, T2SL has demonstrated the feasibility of covering a large infrared detection range, from SWIR to VLWIR [4][5][6], [7] and the capability of growing complex devices with different superlattice structures such as W-structure [8], M-structure [9]. T2SL material system, has demonstrated high performance SWIR [4] and MWIR [5] photodetectors, as well as the dual-band LWIR-LWIR, MWIR-LWIR, MWIR-MWIR photodetectors [10], [11], [12] and imaging [13], [14], [15]. However, up to date, no dual-band SWIR-MWIR photodetector performance has been reported yet.…”