InAsSb-based detectors on GaSb for near-room-temperature operation in the mid-wave infrared

Abstract

III-Sb barrier detectors suitable for the mid-wave infrared were grown on GaSb by molecular beam epitaxy. Using both bulk-InAsSb and an InAsSb-InAs strained layer superlattice, operation close to room temperature was demonstrated with cut-off wavelengths of 4.82 μm and 5.79 μm, respectively, with zero-bias operation possible for the bulk-InAsSb detector. X-ray diffraction, temperature dependent dark current and spectral quantum efficiency were measured, and an analysis based on calculated specific detectivity carried out. 1/f noise effects are considered. Results indicate these optimized devices may be suitable as alternatives to InSb, or even HgCdTe, for many applications, especially where available power is limited.III-Sb alloys and quantum structures are being developed as alternatives to HgCdTe or InSb for mid-wave infrared (MWIR) detectors.[1-4] InSb generally requires cooling to 77 K for acceptable levels of performance and, whilst HgCdTe-based sensors generally still offer the highest signal to noise ratios, they suffer from a lack of large-area native substrates, an acute bandgap-compositional dependence at longer wavelengths, [5] uniformity issues and excessive cost. III-Sb alloys benefit from native 4" GaSb and 3" InAs substrates, lower cost, and the possibility for a wide range of heterostructures with lattice matched materials and alloys, e.g. AlAsSb, InAs, InAsSb or InGaAsSb.[6] Cut-off wavelengths between 1.7 μm and (at least) 12 μm can be achieved using various alloys and strained layer superlattices (SLS).[7-9] However, high dark currents due to trap-related processes and surface recombination are frequently problematic; the community has focussed extensively on developing III-Sb barrier detector designs, which address surface and defect related dark currents using AlSb-based electron-blocking barriers.[10-12] These barrier or "nBn" detectors were first reported using InAs and AlAsSb in 2006.[13] Since then, the design has been widely copied and extended to include InAsSb, e.g. [10] InGaAsSb [6] InAs-GaSb SLS e.g. [14,15] and InAsSb-InAs or "Ga free" SLS e.g. [7][8][9]. In

Room-Temperature Mid-Wave Infrared Guided-Mode Resonance Detectors

“…2(b), as well as the predicted current for an ideal MCT detector calculated using the so-called "Rule 07" [22], a heuristic often used as a benchmark for mid-IR detector dark currents. While our detector dark currents do not approach the recently demonstrated dark currents from MCT detectors leveraging carrier depletion Auger suppression [23], they are below or comparable to Rule 07 for temperatures above 160 K, and well below those of typical III-V semiconductor MWIR photodetectors [24], [25].…”

The Role of Noise in Specific Detectivity of InAs/GaSb Superlattice MWIR Bariodes

“…In this paper, all noise characteristics are shown in the HOT temperature range in addition to the low-temperature characterization. Furthermore, to the best of our knowledge, there are no low-frequency noise measurements reported for bariodes on GaAs substrate, in contrast to recently reported results for various detectors on GaSb substrate [19,21,22].…”

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

“…Gao et al [61] Il'inskaya et al [68] Il'inskaya et al [69] Gao et al [70] KhoshAkhlagh et al [71] Craig et al [26] Deng et al [23] Barli et al [24] Soibel et al [25] Xie et al [72] Craig et al [30] Chen et al [31] the bandgap is available, leading to flexible tunability of the detection wavelength tailored from 3 µm to 32 µm. In other words, by varying the layer thickness with SLs, the detection wavelength of the devices can be extended from the MWIR to terahertz bands.…”