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1

Grating-free high-x InP/InxGa1-xAs mid-wavelength infrared QWIP focal plane array

Besikci Cengiz, Balcı Saadettin V., Tanış Onur, Güngör Oğuz O., Arpaguş Esra S.

Opto-Electronics Review

|

2023

|

Vol. 31, Special Issue

art. no. e144563

EN

The authors report the characteristics of a diffraction-grating-free mid-wavelength infrared InP/In₀.₈₅Ga₀.₁₅As quantum well infrared photodetector focal plane array with a 640 × 512 format and a 15 µm pitch. Combination of a normal incident radiation sensing ability of the high-x InxGa1-xAs quantum wells with a large gain property of the InP barriers led to a diffraction-grating-free quantum well infrared photodetector focal plane array with characteristics displaying great promise to keep the status of the quantum well infrared photodetector as a robust member of the new generation thermal imaging sensor family. The focal plane array exhibited excellent uniformity with noise equivalent temperature difference nonuniformity as low as 10% and a mean noise equivalent temperature difference below 20 mK with f/2 optics at 78 K in the absence of grating. Elimination of the diffraction-grating and large enough conversion efficiency (as high as ~70% at a -3.5 V bias voltage) abolish the bottlenecks of the quantum well infrared photodetector technology for the new generation very small-pitch focal plane arrays.

2

Design and analytical calculations of the width and arrangement of quantum well and barrier layers in GaN/AlGaN LED to enhance the performance

Sharma L., Sharma R.

Opto-Electronics Review

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2021

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Vol. 29, No. 4

141--147

EN

This research paper discusses an analytical approach to designing the active region of light emitting diodes to enhance its performance. The layers in the active region were modified and the effects of changing the width of quantum well and barrier layers in a multi-quantum light emitting diode on the output power and efficiency have been investigated. Also, the ratio of the quantum well width to the B layer width was calculated and proposed in this research paper. The study is carried out on two different LED structures. In the first case (i.e., first structure), the width of the quantum well layers is kept constant while the width of the B layers is varied. In the second case (i.e., second structure), both the quantum well and B layer widths are varied. Based on the simulation results, it has been observed that the LED power efficiency increases considerably for a given quantum well to B layers width ratio without increasing the production complexity. It is also seen that for a desired power efficiency the width of quantum well should be between 0.003 μm and 0.006 μm, and the range of B width (height) should be 2.2 to 6 times the quantum well width. The proposed study is carried out on the GaN-AlGaN-based multi-quantum well LED structure, but this study can be extended to multiple combinations of the semiconductor structures.

3

Peculiarities in optical response of hybrid-barrier GaSb/InAs/AlSb resonant tunneling diode structure

Dyksik M., Motyka M., Rygała M., Pfenning A., Hartmann F., Weih R., Worschech L., Höfling S., Sęk G.

Optica Applicata

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2021

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Vol. 51, nr 2

171--180

EN

We present comprehensive investigation of the optical properties of hybrid-barrier GaSb-based resonant tunneling structures, containing a bulk-like GaInAsSb absorption layer and two asymmetric type II GaSb/InAs/AlSb quantum wells. Methods of optical spectroscopy by means of Fourier-transformed photoluminescence and photoreflectance are employed to probe optical transitions in this complex multilayer system. Based on the comparison between the absorption-like and emission-like spectra (also in function of temperature) confronted with band structure calculations four main transitions could be resolved and identified. For one of them, there has been observed unusually strong linear polarization dependence never reported in structures of that kind. It has been interpreted as related to a transition at the GaSb/GaInAsSb interface, for which various scenarios causing the polarization selectivity are discussed.

4

Emission-intensity-enhanced GaN-based LED based on multilayer grating structures

Li Xin, Sun Dejie, Han Kun, Cao Lijun, Guo Shiliang, Li Zhiquan

Optica Applicata

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2021

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Vol. 51, nr 4

529--540

EN

A novel surface-plasmon-enhanced GaN-LED is proposed to improve the emission efficiency of the traditional LED. The SiO2 film, Ag triangular structure and ITO film were coated on the rectangularly-patterned p-GaN layer sequentially, which can form the quasi-symmetrical waveguide structure to enhance the internal quantum efficiency and the light extraction efficiency. The COMSOL software is used to simulate the LED structure. The radiated powers, absorbed powers and distribution of electric field are obtained and analyzed. The results reveal that emission efficiency of the proposed GaN-LED can be greatly improved.

5

Concepts of infrared and terahertz photodetectors based on vertical graphene van der Waals and HgTe-CdHgTe heterostructures

Ryzhii Maxim, Otsuji Taiichi, Ryzhii Victor, Aleshkin Vladimir, Dubinov Alexander, Karasik V. E., Leiman V., Mitin V., Shur M. S.

Opto-Electronics Review

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2019

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Vol. 27, No. 2

219--223

EN

We review recently proposed concepts of infrared and terahertz photodetectors based on graphene van der Waals heterostructures and HgTe-CdHgTe quantum well heterostructures and demonstrate their potential.

6

Struktura pasmowa i wzmocnienie optyczne studni kwantowych GeSn/Ge

Mączko H., Gładysiewicz M., Kudrawiec R.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 8

13--16

PL

W niniejszej pracy zaprezentowano wyniki obliczeń struktury pasmowej i widm wzmocnienia optycznego dla studni kwantowych Ge/Ge1-xSnx/Ge. Dokonano optymalizacji składu x i grubości studni d do zastosowań w laserach półprzewodnikowych, w wyniku której uzyskano propozycje korzystnych wartości parametrów studni kwantowej: 0,15 < x < 0,17, d ~ 12 mm.

EN

In this work band structure and optical gain was calculated for Ge/Ge1-xSnx/Ge quantum wells. Ottomanization of x composition and the thickness of the well d were made for use in semiconductor lasers. As a result of optimization achieved the optimum parameter values of quantum wells: 0.15 < x < 0.17, d ~ 12 nm.

7

Inhomogeneous GaInNAs quantum wells: their properties and utilization for improving of p-i-n and p-n junction photodetectors

Pucicki D.

Materials Science Poland

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2017

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Vol. 35, No. 4

893--902

EN

A theoretical study of electronic structures and optical properties of GaInNAs/GaAs quantum wells has been performed. The inhomogeneous distributions of indium and nitrogen atoms along the growth direction were discussed as the main factors having significant impact on the QWs absorption efficiency. The study was performed by applying the band anticrossing model combined with the envelope function formalism and based on the material parameters which can be found in the literature. Indeed, the electronic band structure of 15 nm thick uniform Ga0.7In0.3N0.02As0.98/GaAs QW was computed together with electronic structures of several types of inhomogeneous QWs, with the same total content of In and N atoms. It was found that presented inhomogeneities lead to significant quantum wells potential modifications and thus to spatial separation of the electrons and holes wave functions. On the other hand, these changes have a significant impact on the absorption coefficient behavior. This influence has been studied on the basis of simulated photoreflectance spectra, which probe the absorption transitions between QW energy subbands. The electronic structure of inhomogeneous QWs under the influence of electric field has also been studied. Two different senses of electric field vector (of p-i-n and n-i-p junctions) have been considered and thus, the improvement of such types of QWs-photodetectors based on inhomogeneous GaInNAs QWs has been proposed.

8

The role of quantum-well states and carrier scattering times in discontinuities of opto-electrical characteristics of SCH lasers

Kozioł Z, Matukhin S I, Buduleva E A

Optica Applicata

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2014

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Vol. 44, nr 1

135--146

EN

Drift-diffusion computer simulation model available in Synopsys’ Sentaurus TCAD User Guide is used to study electrical and optical characteristics of a separate-confinement heterostructure laser based on AlGaAs. We investigate the role of the width and depth of quantum-well active region, below and above the lasing threshold. The device properties depend on both, the number of bound quantum-well states and on closeness of the highest bound states to conduction or valence band offset. The lasing action may not exist at certain widths or depths of quantum-well, and the threshold current is a discontinuous function of these parameters, at such values of quantum-well width or depth when the highest quantum-well bound states cross conduction or valence band energy offset. The effects are more pronounced at low temperatures. Discontinuities in characteristics are found, at certain conditions, in temperature dependences as well. The carriers scattering time on quantum-well is shown to have a crucial role for the amplitude of discontinuities of these characteristics. The current below the lasing threshold and the threshold current density itself decrease with an increase of quantum-well scattering times and the amplitude of discontinuities decreases then as well.

9

Oscillator strength of optical transitions in InGaAsN/GaAsN/GaAs quantum wells

Mika A, Sek G, Ryczko K, Kozub M, Musial A, Marynski A, Misiewicz J, Langer F, Höfling S, Appel T, Kamp M, Forchel A

Optica Applicata

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2013

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Vol. 43, nr 1

53--60

EN

Experimental and theoretical considerations and results on the effect of nitrogen incorporation on the oscillator strength of optical transitions in InGaNAs/GaAs quantum wells (QWs) are presented. Therefore, a set of dilute nitride quantum well structures was grown by molecular beam epitaxy. Optical investigation via spectroscopic methods have been performed at various temperatures for both the as-grown samples, and after rapid thermal annealing. The fundamental transition energy and its oscillator strength vs. the QW composition have been systematically investigated. Additionally, the effect of the bandgap discontinuities on the transitions intensity has also been considered. The experimental data have been confronted with the band structure calculations within the effective mass approximation employing a two level repulsion model for the nitrogen-containing structures. The obtained results are crucial for possible future applications employing the quantum well in cavity structures and bringing the practical exploitation of quantum electrodynamics phenomena to the telecommunication spectral range.

10

Determination of indium and nitrogen contents of InGaAsN quantum wells by HRXRD study supported by BAC calculation of the measured energy gap

Pucicki D., Bielak K., Kudrawiec R., Radziewicz D., Ściana B.

Materials Science Poland

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2013

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Vol. 31, No. 4

489--494

EN

Determination of indium and nitrogen content in InGaAsN quantum wells (QWs) is often based on the analysis of highresolution X-ray diffraction (HRXRD) measurements. The comparison of diffraction curves of two similar samples, with and without nitrogen, together with an assumption of constant indium incorporation efficiency during the growth of layers with and without nitrogen, may lead to a large deviation in the determined In and N content. The HRXRD curve simulations supported by bandgap determination and calculations seem to be a solution of this problem. Comparison of the results achieved from simulated HRXRD curves with the calculations of all QWs transitions measured by contactless electro-reflectance (CER) can lead to reduction of deviations in composition determination of InGaAsN quantum wells. The proposed algorithm was applied for investigation of InGaAsN QWs grown by atmospheric pressure metalorganic vapor phase epitaxy (APMOVPE).

11

Modelowanie zjawiska spadku sprawności dla dużych gęstości prądów w diodach elektroluminescencyjnych z azotków

Cegielski T.

Prace Instytutu Elektrotechniki

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2012

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Z. 255

7-18

PL

Pomimo rozwoju, który nastąpił w technologii wytwarzania białych elektroluminescencyjnych źródeł światła, w urządzeniach tych ciągle istotną ograniczającą rolę pełni zjawisko spadku sprawności generacji światła dla dużych gęstości prądu. Ponadto wciąż nierozpoznane dostatecznie są jego fizyczne podstawy. W referacie przedstawiono możliwe modele opisujące ten efekt, opierając się na dyskutowanych w literaturze hipotetycznych przyczynach: różnych rodzajach rekombinacji Augera, efektach termicznych, występowaniu silnych pól elektrycznych i asymetrii występowania nośników, itp. Poznanie potencjalnych powodów zjawiska spadku efektywności pozwoli na dalszy rozwój źródeł światła opartych na elektroluminescencji. Przełoży to się na niższy koszt uzyskania zamienników tradycyjnych źródeł światła i większe ich rozpowszechnienie, co w istotny sposób może ograniczyć wzrost światowego zużycia energii.

EN

Despite the development that occurred in the technology of white Light-Emitting Diodes, this devices are still limited by the phenomenon of the efficiency droop that occurs in light generation for large current densities. Moreover, its physical basis is still not sufficiently recognized. The paper presents possible models describing this effect, based on the hypothetical reasons discussed in the literature: different types of Auger recombination, thermal effects, the presence of strong electric fields and the occurrence of the asymmetry of carriers, etc. Knowing the potential reasons for the droop phenomenon will allow the further development of Solid State Light sources. This leads to lower cost retrofits or replacements of traditional light sources and greater their market penetration, which may significantly reduce global energy consumption increase.

12

Comparison studies of infrared photodetectors with a quantum-dot and a quantum-wire base

El-Tokhy M. S., Mahmound I. I., Konber H. A.

Opto-Electronics Review

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2011

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Vol. 19, No. 4

405-417

EN

This paper mainly presents a theoretical analysis for the characteristics of quantum dot infrared photodetectors (QDIPs) and quantum wire infrared photodetectors (QRIPs). The paper introduces a unique mathematical model of solving Poisson's equations with the usage of Lambert W functions for infrared detectors' structures based on quantum effects. Even though QRIPs and QDIPs have been the subject of extensive researches and development during the past decade, it is still essential to implement theoretical models allowing to estimate the ultimate performance of those detectors such as photocurrent and its figure-of-merit detectivity vs. various parameter conditions such as applied voltage, number of quantum wire layers, quantum dot layers, lateral characteristic size, doping density, operation temperature, and structural parameters of the quantum dots (QDs), and quantum wires (QRs). A comparison is made between the computed results of the implemented models and fine agreements are observed. It is concluded from the obtained results that the total detectivity of QDIPs can be significantly lower than that in the QRIPs and main features of the QRIPs such as large gap between the induced photocurrent and dark current of QRIP which allows for overcoming the problems in the QDIPs. This confirms what is evaluated before in the literature. It is evident that by increasing the QD/QR absorption volume in QDIPs/QRIPs as well as by separating the dark current and photocurrents, the specific detectivity can be improved and consequently the devices can operate at higher temperatures. It is an interesting result and it may be benefit to the development of QDIP and QRIP for infrared sensing applications.

13

Overhauser effect and anisotropy of electron spin g-factor in GaAs / AlGaAs quantum wells

Ito T., Shichi W., Ichida M., Gotoh H., Kamada H., Ando H.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 4

105-107

EN

To investigate the dependence of electron g-factor on magnetic field in GaAs / AlGaAs quantum wells time-resolved photoluminescence measurements under a high magnetic field in different experimental configuration, the magnetic field perpendicular (g up tack ) and parallel (g II) to the quantum confinement direction, has been studied. When the angle between the magnetic field and the confinement direction is 45°, the precession frequency varies depending on polarity of magnetic field and the circular polarization type of excitation light (sigma+ or sigma-). We found that these dependences of the precession frequency exhibit main features of Overhauser effect with an effective magnetic field of 0.5 T that nuclear spins react back on electron spin precession and the g-factor value is not affected by the effective magnetic field. The g+ and gii values agree well with the results of four-band k • p perturbation calculations.

14

Output power characteristics of the GaInAs lasers emitting in the spectral range of 1.0 μm

Ivanov A., Kononenko V., Manak I.

Przegląd Elektrotechniczny

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2008

|

R. 84, nr 3

42-44

EN

Luminescence spectra of the quantum-well heterolasers in the GaInAs-GaAs-AlGaAs system are measured, polarization properties of the radiation are analyzed and theoretical description of the emission characteristics is given.

PL

Zbadano charakterystykę widmową lasera GaInAs. Przeanalizowano właściwości polaryzacyjne promieniowania oraz opisano teoretycznie charakterystykę emisyjną.

15

Exciton localization behaviour in different well width undoped GaN/Al₀.₀₇Ga₀.₉₃N nanostructures

Sabooni M., Esmaeili M., Haratizadeh H., Monemar B., Paskov P., Kamiyama S., Iwaya M., Amano H., Akasaki I.

Opto-Electronics Review

|

2007

|

Vol. 15, No. 3

163-167

EN

We report results from optical spectroscopy such as photoluminescence (PL) and time resolved photo-luminescence (TRPL) techniques from different well width MOCVD grown GaN/Al₀.₀₇Ga₀.₉₃N MQW samples. There is evidence of localization at low temperature in all samples. The decay time of all samples becomes non-exponential when the detection energy is increased with respect to the peak of the emission. Localization of carriers (excitons) is demonstrated by the "S-shape" dependences of the PL peak energies on the temperature. The time-resolved PL spectra of the 3-nm well multi quantum wells reveal that the spectral peak position shifts toward lower energies as the decay time increases and becomes red-shifted at longer decay times. There is a gradient in the PL decay time across the emission peak profile, so that the PL process at low temperatures is a free electron-localized hole transition.

16

Optical characterisation of vertical-external-cavity surface-emitting lasers (VECSELs)

Wójcik-Jedlińska A., Piersciński K., Jasik A., Muszalski J., Bugajski M.

Optica Applicata

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2007

|

Vol. 37, nr 4

449-457

EN

The purpose of this paper is to outline the principles of optical characterisation of the new kind of semiconductor devices: vertical-external-cavity surface-emitting lasers (VECSELs). Realisation of high efficiency semiconductor devices requires high accuracy of epitaxial process. Gain characteristic of VECSEL structure is strongly affected by the precise placing of the quantum wells within the multilayer structure. Detailed optical characterisation of particular parts of the structure allows growth errors to be identified and gives insight into the lasing behaviour. In this work, we present an approach taking advantage of two spectroscopic techniques, photoluminescence and reflectance measurements, to study properties of VECSEL structure based on InGaAs/GaAs active region, designed for emission wavelength at 980 nm.

17

Quantum structures for multiband photon detection

Perera A. G. U.

Opto-Electronics Review

|

2006

|

Vol. 14, No. 2

103-112

EN

The work describes multiband photon detectors based on semiconductor micro- and nano-structures. The devices considered include quantum dot, homojunction, and heterojunction structures. In the quantum dot structures, transitions are from one state to another, while free carrier absorption and internal photoemission play the dominant role in homo or heterojunction detectors. Quantum dots-in-a-well (DWELL) detectors can tailor the response wavelength by varying the size of the well. A tunnelling quantum dot infrared photodetector (T-QDIP) could operate at room temperature by blocking the dark current except in the case of resonance. Photoexcited carriers are selectively collected from InGaAs quantum dots by resonant tunnelling, while the dark current is blocked by AlGaAs/InGaAs tunnelling barriers placed in the structure. A two-colour infrared detector with photoresponse peaks at ~6 and ~17 µm at room temperature will be discussed. A homojunction or heterojunction interfacial workfunction internal photoemission (HIWIP or HEIWIP) infrared detector, formed by a doped emitter layer, and an intrinsic layer acting as the barrier followed by another highly doped contact layer, can detect near infrared (NIR) photons due to interband transitions and mid/far infrared (MIR/FIR) radiation due to intraband transitions. The threshold wavelength of the interband response depends on the band gap of the barrier material, and the MIR/FIR response due to intraband transitions can be tailored by adjusting the band offset between the emitter and the barrier. GaAs/AlGaAs will provide NIR and MIR/FIR dual band response, and with GaN/AlGaN structures the detection capability can be extended into the ultraviolet region. These detectors are useful in numerous applications such as environmental monitoring, medical diagnosis, battlefield-imaging, space astronomy applications, mine detection, and remote-sensing.

18

Optimization of multi quantum well solar cell

Prażmowska J., Korbutowicz R.

Optica Applicata

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2005

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Vol. 35, nr 3

619-626

EN

Quantum well solar cell with GaAs wells and AlxGa1-xAs barriers was optimized. Particular emphasis was placed on enhancing the efficiency. Open-circuit voltage, short-circuit current density, fill factor have been also optimized. Many simulations of various structures were carried out. The conversion efficiency exceeding 27% was obtained. The algorithm of structures optimization that gives comprehensive information about solar cells parameters in a short time was shown. Spectral characteristics, efficiency of energy conversion as a function of light concentration, temperature and the geometrical and materials parameters of the solar cells structures were determined. These results are compared with nearly identical p-i-n solar cells: i) the first with /-region made from undoped GaAs (well material) and ii) the second with /-region from A0.1Ga0.9As (barrier material).

19

Optical properties of InGaAsP quantum well for infrared emission investigated by modulation spectroscopy

Podhorodecki A., Andrzejewski J., Motyka M., Kudrawiec R., Misiewicz J., Wójcik J., Robinson B. J.

Optica Applicata

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2005

|

Vol. 35, nr 3

509-515

EN

Modulation spectroscopy, i.e., photoreflectance (PR) and contactless electroreflectance (CER) are very powerful techniques to investigate optical properties of nanostructures. These techniques together with photoluminescence spectroscopy were used for investigation of optical properties of InGaAsP quantum well with infrared emission at 1.55 um. Samples used in this study were grown by gas source molecular beam epitaxy (MBE) on n-doped (100) InP substrate. Based on the numerical calculations the origin of observed optical transitions has been explained and the energy structure of the investigated samples has been proposed.

20

Optical properties of InGaAs/GaAs quantum wells with different distance from Si-delta-doping layer

Motyka M., Sęk G., Andrzejewski J., Kudrawiec R., Misiewicz J., Ściana B., Radziewicz D., Tłaczała M.

Optica Applicata

|

2005

|

Vol. 35, nr 3

471-477

EN

In0.22Ga0.78As/GaAs single quantum wells with different distance from a delta doped layer have been investigated by using contactless electroreflectance (CER) spectroscopy. The oscillator strength of optical transitions and the value of the built-in electric field have been determined from CER spectra. Obtained results have been compared with theoretical calculations preformed in the framework of the effective mass approximation. In order to accurately find the wavefunctions of electrons and holes confined in the quantum well embedded in the built-in electric field, the time-dependent Schrodinger equation has been solved.