High operating temperature split-off band infrared detectors

Perera, A. G. U.; Matsik, S. G.; Jayaweera, P.V.V.; Tennakone, K.; Liu, H. C.; Buchanan, M.; Winckel, G. von; Stintz, A.; Krishna, S.

doi:10.1063/1.2358106

Cited by 26 publications

(35 citation statements)

References 13 publications

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“…Detailed explanations of detection mechanism, as well as details of the growth of all structures, have been reported previously in Pitigala, et al 11,12 .…”

Section: Device Structures and Experimental Proceduresmentioning

confidence: 99%

“…The excited carriers then escape from the emitter layer after scattering out of split-off band back into the light/heavy hole band at the emitter-barrier interface 11 as shown in Figure 1. Detailed explanations of detection mechanism, as well as details of the growth of all structures, have been reported previously in Pitigala, et al 11,12 .…”

Section: Device Structures and Experimental Proceduresmentioning

confidence: 99%

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Low-frequency noise properties of p-type GaAs/AlGaAs heterojunction detectors

Wolde

Lao

Pitigala

et al. 2016

Infrared Physics & Technology

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We have measured and analyzed, at different temperatures and bias voltages, the dark noise spectra of GaAs/AlGaAs heterojunction infrared photodetectors, where a highly doped GaAs emitter is sandwiched between two AlGaAs barriers. The noise and gain mechanisms associated with the carrier transport are investigated, and it is shown that a lower noise spectral density is observed for a device with a flat barrier, and thicker emitter. Despite the lower noise power spectral density of flat barrier device, comparison of the dark and photocurrent noise gain between flat and graded barrier samples confirmed that the escape probability of carriers (or detectivity) is enhanced by grading the barrier. The grading suppresses recombination owing to the higher momentum of carriers in the barrier. Optimizing the emitter thickness of the graded barrier to enhance the absorption efficiency, and increase the escape probability and lower the dark current, enhances the specific detectivity of devices.

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“…Detailed explanations of detection mechanism, as well as details of the growth of all structures, have been reported previously in Pitigala, et al 11,12 .…”

Section: Device Structures and Experimental Proceduresmentioning

confidence: 99%

Section: Device Structures and Experimental Proceduresmentioning

confidence: 99%

Low-frequency noise properties of p-type GaAs/AlGaAs heterojunction detectors

Wolde

Lao

Pitigala

et al. 2016

Infrared Physics & Technology

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“…The IR response arising from split off band transitions in a p-doped GaAs/Al 0.12 Ga 0.88 As heterostructure was initially reported by Perera et al at 77 K. 13 Thereafter, higher operating temperature split-off band IR detectors were demonstrated by Jayaweera et al 12 using high aluminum mole fractions (x), where x ¼ 0.28, 0.38, and 0.57, in the Al x Ga (1Àx) As barriers; this led to devices operating uncooled with x ¼ 0.57. Subsequently, Matsik et al…”

Section: Introductionmentioning

confidence: 99%

Performance improvements of a split-off band infra-red detector using a graded barrier

Pitigala

Lao

Perera

et al. 2014

Journal of Applied Physics

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Uncooled split-off band infrared detectors have been demonstrated with an operational device response in the 3–5 μm range. We have shown that it is possible to enhance this device response through reducing the recapture rate by replacing one of the commonly used flat barriers in the device with a graded barrier, which was grown using a “digital alloying” approach. Responsivity of approximately 80 μA/W (D* = 1.4 × 108 Jones) were observed at 78 K under a 1 V applied bias, with a peak response at 2.8 μm. This is an improvement by a factor of ∼25 times compared to an equivalent device with a flat barrier. This enhancement is due to improved carrier transport resulting from the superlattice structure, and a low recapture rate enabled by a reduced distance to the image force potential peak in the graded barrier. The device performance can be further improved by growing a structure with repeats of the single emitter layer reported here.

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“…Depending on their energy, the holes can escape to either the S-O band or the H-H/L-H bands in the barrier. A detailed account of possible escape pathways is provided elsewhere, 17 but the asymmetry of the GaAs/ Al x Ga 1-x As barriers plays an important role in driving the holes, even in the absence of an applied bias. Therefore, a net photocurrent can be observed under photovoltaic operation.…”

Section: Device Design and Experimentsmentioning

confidence: 99%

Mid-infrared detection in p-GaAs/AlGaAs heterostructures with a current blocking barrier

Chauhan

Perera

et al. 2017

SPIE Proceedings

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For the infrared detection in the 3-5 µm range, p-GaAs/Al x Ga 1-x As heterojunction is an attractive material system due to light hole/heavy hole and spin-orbit split-off intra-valance band transitions in this wavelength range. Varying the Al mole fraction (x) provides the tuning for the wavelength threshold, while graded Al x Ga 1-x As potential barriers create an asymmetry to allow a photovoltaic operation. The photovoltaic mode of operation offers the advantage of thermal noise limited performance. In our preliminary work, a 2 -6 µm photovoltaic detector was studied. Implementation of an additional current blocking barrier improved the specific detectivity (D*) by two orders of magnitude, to 1.9×10 11 Jones at 2.7 µm, at 77K. At zero bias, the resistance-area product (R 0 A) had a value of ~ 7.2×10 8 cm 2 , which is five orders higher in magnitude (with a corresponding reduction of the responsivity by only a factor of ~ 1.5), compared to the R 0 A value without the blocking barrier. A photoresponse was observed up to 130K.

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High operating temperature split-off band infrared detectors

Cited by 26 publications

References 13 publications

Low-frequency noise properties of p-type GaAs/AlGaAs heterojunction detectors

Low-frequency noise properties of p-type GaAs/AlGaAs heterojunction detectors

Performance improvements of a split-off band infra-red detector using a graded barrier

Mid-infrared detection in p-GaAs/AlGaAs heterostructures with a current blocking barrier

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