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Barrier in the valence band in the nBn detector with an active layer from the type-II superlattice

Kopytko Małgorzata, Gomółka Emilia, Manyk Tetiana, Michalczewski Krystian, Kubiszyn Łukasz, Rutkowski Jaroslaw, Martyniuk Piotr

Opto-Electronics Review

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2021

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Vol. 29, No. 1

1--4

EN

Numerical analysis of the dark current (Id) in the type-II superlattice (T2SL) barrier (nBn) detector operated at high temperatures was presented. Theoretical calculations were compared with the experimental results for the nBn detector with the absorber and contact layers in an InAs/InAsSb superlattice separated AlAsSb barrier. Detector structure was grown using MBE technique on a GaAs substrate. The k·p model was used to determine the first electron band and the first heavy and light hole bands in T2SL, as well as to calculate the absorption coefficient. The paper presents the effect of the additional hole barrier on electrical and optical parameters of the nBn structure. According to the principle of the nBn detector operation, the electrons barrier is to prevent the current flow from the contact layer to the absorber, while the holes barrier should be low enough to ensure the flow of optically generated carriers. The barrier height in the valence band (VB) was adjusted by changing the electron affinity of a ternary AlAsSb material. Results of numerical calculations similar to the experimental data were obtained, assuming the presence of a high barrier in VB which, at the same time, lowered the detector current responsivity.

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Demonstration of HOT photoresponse of MWIR T2SLs InAs/InAsSb photoresistors

Michalczewski Krystian, Tsai T. Y., Martyniuk P., Wu C. H.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 1

141--145

EN

We report on the photoresponse of mid-wavelength infrared radiation (MWIR) type-II superlattices (T2SLs) InAs/InAsSb high operating temperature (HOT) photoresistor grown on GaAs substrate. The device consists of a 200 periods of active layer grown on GaSb buffer layer. The photoresistor reached a 50% cut-off wavelength of 5 μm and 6 μm at 200 K and 300 K respectively. The time constant of 30 ns is observed at 200 K under 1 V bias. This is the first observation of the photoresponse in MWIR T2SLs InAs/InAsSb above 200 K..

3

Type-II superlattice detectors for free space optics applications and higher operating temperature conditions

Hackiewicz K., Martyniuk P., Rutkowski J., Manyk T., Mikołajczyk J.

Opto-Electronics Review

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2018

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Vol. 26, No. 4

279--284

EN

The utmost limit performance of interband cascade detectors optimized for the longwave range ofinfrared radiation is investigated in this work. Currently, materials from the III–V group are character-ized by short carrier lifetimes limited by Shockley-Read-Hall generation and recombination processes.The maximum carrier lifetime values reported at 77 K for the type-II superlattices InAs/GaSb andInAs/InAsSb in a longwave range correspond to ∼200 and ∼400 ns. We estimated theoretical detectivityof interband cascade detectors assuming above carrier lifetimes and a value of ∼1–50μs reported for awell-known HgCdTe material. It has been shown that for room temperature the limit value of detctivityis of ∼3–4×10¹⁰cmHz½/W for the optimized detector operating at the wavelength range ∼10μm couldbe reached.

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Detektory barierowe : nowe trendy

Martyniuk P., Kopytko M., Rogalski A.

Elektronika : konstrukcje, technologie, zastosowania

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2016

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Vol. 57, nr 9

62--65

PL

W artykule omówiono nowe trendy w rozwoju wysokotemperaturowych – nie wymagających chłodzenia kriogenicznego – barierowych detektorów podczerwieni. Przedstawiono podstawy teoretyczne, podstawową strukturę typu nBn, jak również dokonano przeglądu materiałów wykorzystywanych do wytwarzania detektorów barierowych pod względem granicznych wartości prądu ciemnego. Przedstawiono osiągi detektorów barierowych wytwarzanych z supersieci-II rodzaju materiałów grupy AIIIBV InAs/GaSb i InAs/InAsSb. W przypadku InAs/InAsSb szacowania teoretyczne wskazują na lepsze osiągi niż te uzyskiwane dla układu InAs/GaSb. Nie pominięto materiałów objętościowych z grupyAIIIBV: InAs, InAsSb i InGaAsSb, jak również dominującego obecnie HgCdTe. Detektory barierowe związków grupyAIIIBV, zarówno z materiałów litych jak i z supersieci-II typu, stanowią realną alternatywę dla HgCdTe do zastosowań wysokotemperaturowych, choć najniższe graniczne wartości prądu nadal uzyskuje się dla struktur z HgCdTe.

EN

In the paper we discussed the new trends in higher operating temperature – exhibiting no requirements related to the cryogenic cooling – the barrier IR detectors. We presented basic theory, simple nBn structure, and reviewed the materials used for the nBn detectors in terms of the utmost dark current. The performance was presented for type-II superllatices InAs/GaSb and InAs/InAsSb. Theoretical simulations indicate that T2SLs InAs/InAsSb exhibits lower SRH generation recombination rates in comparison to the InAs/GaSb. The performance of the bulk InAsSb and HgCdTe materials was also presented. TheAIIIBV bulk and type-II superlattices barrier detectors could be treated as an alternative to the HgCdTe detectors for higher operating temperature conditions. The utmost dark current was found for HgCdTe nBn barrier detectors.