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1

Investigation of HgCdTe avalanche photodiodes for HOT condition

Manyk Tetiana, Sobieski Jan, Matuszelański Kacper, Rutkowski Jarosław, Martyniuk Piotr

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 3

art. no. e149173

EN

The performance of long-wave infrared (LWIR) x = 0.22 HgCdTe avalanche photodiodes (APDs) was presented. The dark currentvoltage characteristics at temperatures 200 K, 230 K, and 300 K were measured and numerically simulated. Theoretical modeling was performed by the numerical Apsys platform (Crosslight). The effects of the tunneling currents and impact ionization in HgCdTe APDs were calculated. Dark currents exhibit peculiar features which were observed experimentally. The proper agreement between the theoretical and experimental characteristics allowed the determination that the material parameters of the absorber were reached. The effect of the multiplication layer profile on the detector characteristics was observed but was found to be insignificant.

2

MCT heterostructures for higher operating temperature infrared detectors designed in Poland

Madejczyk Paweł, Gawron Waldemar, Sobieski Jan, Martyniuk Piotr, Rutkowski Jarosław

Opto-Electronics Review

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2023

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Vol. 31, Special Issue

art. no. e144551

EN

This paper presents examples of infrared detectors with mercury cadmium telluride elaborated at the Institute of Applied Physics, Military University of Technology and VIGO Photonics S.A. Fully doped HgCdTe epilayers were grown with the metal organic chemical vapour deposition technique which provides a wide range of material composition covering the entire infrared range from 1.5 μm to 14 μm. Fundamental issues concerning the design of individual areas of the heterostructure including: the absorber, contacts, and transient layers with respect to their thickness, doping and composition were discussed. An example of determining the gain is also given pointing to the potential application of the obtained devices in avalanche photodiode detectors that can amplify weak optical signals. Selected examples of the analysis of current-voltage and spectral characteristics are shown. Multiple detectors based on a connection in series of small individual structures are also presented as a solution to overcome inherent problems of low resistance of LWIR photodiodes. The HgCdTe detectors were compared with detectors from III-V materials. The detectors based on InAs/InAsSb superlattice materials achieve very comparable parameters and, in some respects, they are even superior to those with mercury cadmium telluride.

3

HgCdTe energy gap determination from photoluminescence and spectral response measurements

Murawski Krzysztof, Kopytko Małgorzata, Madejczyk Paweł, Majkowycz Kinga, Martyniuk Piotr

Metrology and Measurement Systems

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2023

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Vol. 30, nr 1

183--194

EN

The temperature dependence of photoluminescence spectra has been studied for the HgCdTe epilayer. At low temperatures, the signal has plenty of band-tail states and shallow/deep defects which makes it difficult to evaluate the material bandgap. In most of the published reports, the photoluminescence spectrum containing multiple peaks is analyzed using a Gaussian fit to a particular peak. However, the determination of the peak position deviates from the energy gap value. Consequently, it may seem that a blue shift with increasing temperature becomes apparent. In our approach, the main peak was fitted with the expression proportional to the product of the joint density of states and the Boltzmann distribution function. The energy gap determined on this basis coincides in the entire temperature range with the theoretical Hansen dependence for the assumed Cd molar composition of the active layer. In addition, the result coincides well with the bandgap energy determined on the basis of the cut-off wavelength at which the detector response drops to 50% of the peak value.

4

The determination of the carriers recombination parameters based on the HOT HgCdTe current-voltage characteristics

Manyk Tetiana, Rutkowski Jarosław, Madejczyk Paweł, Gawron Waldemar, Martyniuk Piotr

Opto-Electronics Review

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2022

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Vol. 30, No. 2

art. no. e141596

EN

A theoretical analysis of the mid-wavelength infrared range detectors based on the HgCdTe materials for high operating temperatures is presented. Numerical calculations were compared with the experimental data for HgCdTe heterostructures grown by the MOCVD on the GaAs substrates. Theoretical modelling was performed by the commercial platform SimuAPSYS (Crosslight). SimuAPSYS fully supports numerical simulations and helps understand the mechanisms occurring in the detector structures. Theoretical estimates were compared with the dark current density experimental data at the selected characteristic temperatures: 230 K and 300 K. The proper agreement between theoretical and experimental data was reached by changing Auger-1 and Auger-7 recombination rates and Shockley-Read-Hall carrier lifetime. The level of the match was confirmed by a theoretical evaluation of the current responsivity and zero-bias dynamic resistance area product (R0A) of the tested detectors.

5

Signal processing for time resolved photoluminescence spectroscopy

Grodecki Kacper, Murawski Krzysztof, Rutkowski Jarosław, Kowalewski Andrzej, Sobieski Jan

Opto-Electronics Review

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2021

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Vol. 29, No. 3

91--96

EN

Accurate determination of material parameters, such as carrier lifetimes and defect activation energy, is a significant problem in the technology of infrared detectors. Among many different techniques, using the time resolved photoluminescence spectroscopy allows to determine the narrow energy gap materials, as well as their time dynamics. In this technique, it is possible to observe time dynamics of all processes in the measured sample as in a streak camera. In this article, the signal processing for the above technique for Hg1-xCdxTe with a composition x of about 0.3 which plays an extremely important role in the mid-infrared is presented. Machine learning algorithms based on the independent components analysis were used to determine components of the analyzed data series. Two different filtering techniques were investigated. In the article, it is shown how to reduce noise using the independent components analysis and what are the advantages, as well as disadvantages, of selected methods of the independent components analysis filtering. The proposed method might allow to distinguish, based on the analysis of photoluminescence spectra, the location of typical defect levels in HgCdTe described in the literature.

6

Recent infrared detector technologies, applications, trends and development of HgCdTe based cooled infrared focal plane arrays and their characterization

Bhan R. K., Dhar Vikram

Opto-Electronics Review

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2019

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Vol. 27, No. 2

174--193

EN

Infrared thermal imaging, using cooled and uncooled detectors, is continuously gaining attention because of its wide military and civilian applications. Futuristic requirements of high temperature operation, multispectral imaging, lower cost, higher resolution (using pixels) etc. are driving continuous developments in the field. Although there are good reviews in the literature by Rogalski [1–4], Martyniuk et al. [5] and Rogalski et al. [6] on various types of infrared detectors and technologies, this paper focuses on some of the important recent trends and diverse applications in this field and discusses some important fundamentals of these detectors.

7

MBE-grown MCT hetero- and nanostructures for IR and THz detectors

Dvoretsky S. A., Mikhailov N. N., Remesnik V. G., Sidorov Y. G., Shvets V. A., Ikusov D. G., Varavin V. S., Yakushev M. V., Gumenjuk-Sichevska J. V., Golenkov A. G., Lysiuk I. O., Tsybrii Z. F., Shevchik-Shekera A. V., Sizov F. F., Latyshev A. V., Aseev A. L.

Opto-Electronics Review

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2019

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Vol. 27, No. 3

282--290

EN

We present an overview of our technological achievements in the implementation of detector structures based on mercury cadmium telluride (MCT) heterostructures and nanostructures for IR and THz spectral ranges. We use a special MBE design set for the epitaxial layer growth on (013) GaAs substrates with ZnTe and CdTe buffer layers up to 3” in diameter with the precise ellipsometric monitoring in situ. The growth of MCT alloy heterostructures with the optimal composition distribution throughout the thickness allows the realization of different types of many-layered heterostructures and quantum wells to prepare the material for fabricating single- or dual-band IR and THz detectors. We also present the two-color broad-band bolometric detectors based on the epitaxial MCT layers that are sensitive in 150–300-GHz subterahertz and infrared ranges from 3 to 10μm, which operate at the ambient or liquid nitrogen temperatures as photoconductors, as well as the detectors based on planar HgTe quantum wells. The design and dimensions of THz detector antennas are optimized for reasonable detector sensitivity values. A special diffraction limited optical system for the detector testing was designed and manufactured. We represent here the THz images of objects hidden behind a plasterboard or foam plastic packaging, obtained at the radiation frequencies of 70, 140, and 275 GHz, respectively.

8

Effect of annealing on the structural properties of arsenic-implanted mercury cadmium telluride

Izhnin Ihor, Fitsych Olena I., Świątek Z., Morgiel Y., Bonchyk Oleksandr Yu, Savytskyy Hrygoriy V., Mynbaev Karim, Voitsekhovskii Alexander V., Korotaev Alexander G., Yakushev Maksim Vitalievich, Marin Denis V., Varavin Vasilii S., Dvoretsky Sergey Alekseevich

Opto-Electronics Review

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2019

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Vol. 27, No. 1

14--17

EN

Effect of annealing on the structural properties of arsenic-implanted mercury cadmium telluride film grown by molecular beam epitaxy was studied with the use of transmission electron microscopy and optical reflection. Strong influence of the graded-gap surface layer grown on top of the film on the behaviour of implantation-induced defects under arsenic activation annealing was revealed and interpreted.

9

Ion etching of HgCdTe : properties, patterns and use as a method for defect studies

Izhnin I. I., Mynbaev K. D., Voitsekhovskii A. V., Korotaev A. G., Fitsych O. I., Pociask-Bialy M.

Opto-Electronics Review

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2017

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Vol. 25, No. 2

148--170

EN

Analysis is performed of the contemporary views on the effect of ion etching (ion-beam milling and reactive ion etching) on physical properties of HgCdTe and on the mechanisms of the processes responsible for modification of these properties under the etching. Possibilities are discussed that ion etching opens for defect studies in HgCdTe, including detecting electrically neutral tellurium nanocomplexes, determining background donor concentration in the material of various origins, and understanding the mechanism of arsenic incorporation in molecular-beam epitaxy-grown films.

10

Theoretical Simulation of a Room Temperature HgCdTe Long-Wave Detector for Fast Response - Operating Under Zero Bias Conditions

Martyniuk P., Kopytko M., Madejczyk P., Henig A., Grodecki K., Gawron W., Rutkowski J.

Metrology and Measurement Systems

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2017

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Vol. 24, nr 4

729--738

EN

The paper reports on a long-wave infrared (cut-off wavelength ~ 9 μm) HgCdTe detector operating under nbiased condition and room temperature (300 K) for both short response time and high detectivity operation. The ptimal structure in terms of the response time and detectivity versus device architecture was shown. The response time of the long-wave (active layer Cd composition, xCd = 0.19) HgCdTe detector for 300 K was calculated at a level of τs ~ 1 ns for zero bias condition, while the detectivity - at a level of D* ~ 109 cmHz1/2/W assuming immersion. It was presented that parameters of the active layer and P+ barrier layer play a critical role in order to reach τs ≤ 1 ns. An extra series resistance related to the processing (RS+ in a range 5-10 Ω) increased the response time more than two times (τs ~ 2.3 ns).

11

Fast Response Hot (111) HGCDTE MWIR Detectors

Grodecki K., Martyniuk P., Kopytko M., Kowalewski A., Stępień D., Kębłowski A., Piotrowski A., Piotrowski J., Gawron W., Rogalski A.

Metrology and Measurement Systems

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2017

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Vol. 24, nr 3

509--514

EN

In this work we report simulation and experimental results for an MWIR HgCdTe photodetector designed by computer simulation and fabricated in a joint laboratory run by VIGO Sytems S.A. and Military University of Technology. The device is based on a modified N+pP+ heterostructure grown on 2”., epiready, semi-insulating (100) GaAs substrates in a horizontal MOCVD AIX 200 reactor. The devices were examined by measurements of spectral and time responses as a function of a bias voltage and operating temperatures. The time response was measured with an Optical Parametric Oscillator (OPO) as the source of ~25 ps pulses of infrared radiation, tuneable in a 1.55–16 μm spectral range. Two-stage Peltier cooled devices (230 K) with a 4.1 μm cut-off wavelength were characterized by 1.6 × 1012 cm Hz1/2/W peak detectivity and < 1 ns time constant for V > 500 mV.

12

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.

13

Status of long-wave Auger suppressed HgCdTe detectors operating > 200 K

Martyniuk P., Gawron W., Stępień D., Pawluczyk J., Kębłowski A., Madejczyk P., Kopytko M., Koźniewski A.

Opto-Electronics Review

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2015

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Vol. 23, No. 4

278-286

EN

We report on the status of long-wave infrared Auger suppressed HgCdTe multilayer structures grown on GaAs substrates designed for high operating temperature condition: 200-300 K exhibiting, detectivity ~10¹¹ cmHz¹/² /W, time response within a ~120 ps range at 230 K. Abnormal responsivity within the range of ~30 A/W for electrical area 30×30 μm² under reverse bias V = 150 mV is reported. Maximum extraction coefficient of ~2.3 was estimated for analysed structures.

14

Different cap-barrier design for MOCVD grown HOT HgCdTe barrier detectors

Kopytko M., Kębłowski A., Gawron W., Madejczyk P.

Opto-Electronics Review

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2015

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Vol. 23, No. 2

143-148

EN

The performance of HgCdTe barrier detectors with cut-off wavelengths up to 3.6 μm fabricated using metaloorganic chemical vapour deposition operated at high temperatures is presented. The detectors’ architecture consists of four layers: cap contact, wide bandgap barrier, absorber and bottom contact layer. The structures were fabricated both with n- and p-type absorbing layers. In the paper, different design of cap-barrier structural unit (n-Bp', n+-Bp', p+-Bp) were analysed in terms of various electrical and optical properties of the detectors, such as dark current, current responsivity time constant and detectivity. The devices with a p-type cap contact exhibit very low dark current densities in the range of (2÷3)×10⁻⁴ A/cm² at 230 K and the maximum photoresponse of about 2 A/W in wide range of reverse bias voltage. The time constant of measured de- vices with n-type cap contact and p-type absorbing drops below 1 ns with reverse bias while the detectivity is at the level of 1010 cm・Hz1/2/W.

15

Background donor concentration in HgCdTe

Izhnin I. I., Mynbaev K. D., Voitsekhovsky A. V., Korotaev A. G., Fitsych O. I., Pociask-Bialy M., Dvoretsky S. A.

Opto-Electronics Review

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2015

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Vol. 23, No. 3

200-207

EN

Studies of background donor concentration (BDC) in HgCdTe samples grown with different types of technology were performed with the use of ion milling as a means of eliminating the compensating acceptors. In bulk crystals, films grown with liquid phase epitaxy and films fabricated with molecular beam epitaxy (MBE) on Si substrates, BDC of the order of ~10¹⁴ cm⁻³ was revealed. Films grown with metal-organic chemical vapour deposition and with MBE on GaAs substrates showed BDC of the order of ~10¹⁵ cm⁻³. A possibility of assessing the BDC in acceptor (arsenic)-doped HgCdTe was demonstrated. In general, the studies showed the effectiveness of ion milling as a method of reducing electrical compensation in n-type MCT and as an excellent tool for assisting evaluation of BDC.

16

Influence of composition of the near-surface graded-gap layer on the admittance of metal-insulator-semiconductor structures based on graded-gap MBE n-Hg₁₋xCdxTe in wide temperature range

Voitsekhovskii A. V., Nesmelov S. N., Dzyadukh S. M.

Opto-Electronics Review

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2014

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Vol. 22, No. 4

236-244

EN

Influence of the CdTe content in a near-surface graded-gap layer on the admittance of MIS-structures fabricated on the basis of heteroepitaxial Hg₁₋xCdxTe (x = 0.22−0.23 and 0.31−0.32) films grown by molecular beam epitaxy was investigated in a wide temperature range. It is shown that a temperature drop from 77 K to 8 K results in a decrease of hysteresis of the capacitance-voltage (C−V) characteristics and a decrease of frequencies which corresponds to a high-frequency behaviour of C−V characteristics of MIS-structures based on n-HgCdTe (x = 0.22–0.23) with and without graded-gap layersand also for MIS-structures based on n-HgCdTe (x = 0.31–0.32). Temperature dependences of the resistance of the epitaxial film bulk and differential resistance of the space-charge region (SCR) in strong inversion mode were studied. The experimental results can be explained by the fact that for MIS-structures based on n-HgCdTe (x = 0.22–0.23) with the graded-gap layers and for MIS-structures based on n-HgCdTe (x = 0.31–0.32), the differential resistance of SCR is limited by Shockley-Read generation at 25–77 K. Differential resistance of SCR for MIS-structures based on n-HgCdTe (x = 0.22–0.23) without the graded-gap layers is limited by tunnelling through deep levels at 8–77 K.

17

Photoluminescence of HgCdTe nanostructures grown by molecular beam epitaxy on GaAs

Izhnin I. I., Izhnin A. I., Mynbaev K. D., Bazhenov N. L., Shilyaev A. V., Mikhailov N. N., Varavin V. S., Dvoretsky S. A., Fitsych O. I., Voitsekhovsky A. V.

Opto-Electronics Review

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2013

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Vol. 21, No. 4

390-394

EN

Photoluminescence (PL) of HgCdTe-based hetero-epitaxial nanostructures with 50 to 1100 nm-wide potential wells was studied. The nanostructures were grown by molecular beam epitaxy on GaAs substrates. A strong degree of alloy disorder was found in the material, which led to the broadening of the PL spectra and a considerable Stokes shift that could be traced up to temperature T~230 K. Annealing of the structures improved the ordering and led to the increase in the PL intensity. A remarkable feature of the PL was an unexpectedly small decrease of its intensity with temperature increasing from 84 to 300 K. This effect can be related to localization of carriers at potential fluctuations and to the specific character of Auger-type processes in HgCdTe-based nanostructures.

18

Electrical properties of HgCdTe films grown by MOCVD and doped with as

Izhnin I. I., Savytskyy H. V., Fitsych O. I., Piotrowski J., Mynbaev K. D.

Opto-Electronics Review

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2013

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Vol. 21, No. 2

220-226

EN

Electrical properties of HgCdTe films grown by metal-organic chemical vapour deposition (MOCVD) on GaAs substrates and doped with the As acceptor during the growth were studied. Discrete mobility spectrum analysis was used to extract the parameters of the as-grown films and films after ion milling and during prolonged relaxation of milling-induced defects. The measurements revealed significant compensation of the as-grown MOCVD HgCdTe with As on Te sites being the main defect, residual donor concentration of the order of (2-5)x10¹⁵ cm⁻³ and the presence of some unidentified defects.

19

Modeling of HgCdTeLWIR detector for high operation temperature conditions

Martyniuk P., Gawron W., Madejczyk P., Rogalski A., Piotrowski J.

Metrology and Measurement Systems

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2013

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Vol. 20, nr 2

159--170

EN

The paper reports on the photoelectrical performance of the long wavelength infrared (LWIR) HgCdTe high operating temperature (HOT) detector. The detector structure was simulated with commercially available software APSYS by Crosslight Inc. taking into account SRH, Auger and tunnelling currents. A detailed analysis of the detector performance such as dark current, detectivity, time response as a function of device architecture and applied bias is performed, pointing out optimal working conditions.

20

Szumy małej częstotliwości detektorów nBn na zakres średniej podczerwieni wykonanych z supersieci II rodzaju InAs/GaSb z barierą Al0.2Ga0.8Sb

Ciura Ł., Kolek A., Kowalewski A., Gawron W.

Elektronika : konstrukcje, technologie, zastosowania

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2013

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Vol. 54, nr 11

88-91

PL

W pracy przedstawiono pomiary szumów małej częstotliwości detektora średniej podczerwieni typu nBn wykonanego na bazie supersieci II-rodzaju InAs/GaSb z barierą Al0.2Ga0.8Sb. Badania przeprowadzono w temperaturze 77K. Pokazano, że widma szumów są superpozycją lorencjanów o różnych stałych czasowych. Dla małych prądów szum 1/f powiązano z fluktuacjami rezystancji upływu S1(f) ~ U/2/IRsh2. W zakresie napięć, gdzie dominują prądy tunelowe, zaobserwowano zależność S1(f) ~ /I. Wyniki pomiarów porównano z szumami m. cz. fotodiody z HgCdTe.

EN

In this paper low frequency noise of mid-wavelength infrared detector nBn made of II-type superlattices InAs/GaSb with barrier Al0.2Ga0.8Sb was shown. Measurements at temperature 77K was done. It was concluded that power spectral density is a sum of several lorentzians with different time constants. For small currents 1/f noise was connected with fluctuations of leakage resistance S1(f) ~ U2IRsh2. When tunneling currents dominate in total dark current relationship S1(f) ~ I was observed. Results of the noise measurements was compared with low frequency noise of the photodiode p-n based on HgCdTe.