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Tytuł:
Korelacyjny pomiar gęstości widmowej mocy szumów detektorów fotonowych do spektroskopii absorpcyjnej
Cross-correlation method for noise measurements of photodetectors used for laser absorption spectroscopy
Autorzy:
Achtenberg, Krzysztof
Mikołajczyk, Janusz
Bielecki, Zbigniew
Wojtas, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1857073.pdf
Data publikacji:
2020
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
szumy
detektory IR
spektroskopia absorpcyjna w podczerwieni
detektor supersieciowy
noise
infrared detectors
infrared absorption spectroscopy
superlattice detector
Opis:
W pracy przedstawiono wyniki pomiarów gęstości widmowej napięcia szumów detektorów fotonowych o małych rezystancjach przy użyciu specjalnie opracowanego stanowiska pomiarowego. Badania tych detektorów mają duże znaczenie dla wielu aplikacji. Są one szczególnie istotne dla układów laserowej spektroskopii absorpcyjnej do wykrywania śladowych ilości gazów. Uzyskiwana w nich granica wykrywalności jest bezpośrednio związana nie tylko z szumami źródeł promieniowania i szumem tła, lecz także z szumami detektora oraz kolejnych stopni fotoodbiornika. Zastosowanie w opracowanym systemie specjalnie zaprojektowanych ultramałoszumowych torów pomiarowych (wzmacniacze o napięciu szumów 3,6 × 10⁻¹⁹ V² /Hz dla f > 1 kHz) oraz operacji korelacji sygnałów w czasie 10 minut umożliwiło uzyskanie szumu tła poniżej 10⁻¹⁸ V² /Hz dla f > 10 Hz oraz poniżej 10⁻¹⁹ V² /Hz dla f > 1 kHz. Efektywność systemu zweryfikowano poprzez pomiary referencyjnych rezystorów, a następnie detektora z supersieci drugiego rodzaju (T2SL) wykonanego z InAs/InAsSb.
The paper presents noise measurements of low-resistance photon detectors with a specially developed system. These measurements are significant for many applications. This issue is particularly critical for laser absorption spectroscopy systems to detect trace amounts of gases. In these systems, the detection limit is determined by noise origins, e.g., light source, background, and detector noise and its readout electronics. The use of some specially designed components of the system (low-noise - 3.6 × 10⁻¹⁹ V² /Hz for f >1 kHz) cross-correlation signal processing provides to obtain a measuring floor noise below 10⁻¹⁸ V² /Hz for f > 10 Hz and below 10⁻¹⁹ V² /Hz for f > 1 kHz after ten minutes’ analysis. Measurements of some reference resistors have verified the system’s performance. Finally, the system was also applied to determine the spectral noise density of the II-Type SuperLattice photodetector made of InAs/InAsSb.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2020, 69, 4; 73-83
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of an InAs/GaSb superlattice barrier photodetector covering the full LWIR spectral domain
Autorzy:
Alchaar, R.
Rodriguez, J.-B.
Höglund, L.
Naureen, S.
Costard, E.
Christol, P.
Powiązania:
https://bibliotekanauki.pl/articles/1818247.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
barrier photodetector
InAs/GaSb type-2 superlattice
long wavelength infrared
performance analysis
Opis:
In this paper, we present the electrical and electro-optical characterizations of an InAs/GaSb type-2 superlattice barrier photodetector operating in the full longwave infrared spectral domain. The fabricated detectors exhibited a 50% cut-off wavelength around 14 μm at 80 K and a quantum efficiency slightly above 20%. The dark current density was of 4.6×10⁻² A/cm² at 80 K and a minority carrier lateral diffusion was evaluated through dark current measurements on different detector sizes. In addition, detector spectral response, its dark current-voltage characteristics and capacitance-voltage curve accompanied by electric field simulations were analyzed in order to determine the operating bias and the dark current regimes at different biases. Finally, dark current simulations were also performed to estimate a minority carrier lifetime by comparing experimental curves with simulated ones.
Źródło:
Opto-Electronics Review; 2020, 28, 3; 164--170
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of an InAs/GaSb superlattice barrier photodetector covering the full LWIR spectral domain
Autorzy:
Alchaar, Rodolphe
Rodriguez, Jean-Baptiste
Höglund, L.
Naureen, Shagufta
Costard, Eric
Christol, Philippe
Powiązania:
https://bibliotekanauki.pl/articles/1818240.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
barrier photodetector
InAs/GaSb type-2 superlattice
long wavelength infrared
performance analysis
Opis:
In this paper, we present the electrical and electro-optical characterizations of an InAs/GaSb type-2 superlattice barrier photodetector operating in the full longwave infrared spectral domain. The fabricated detectors exhibited a 50% cut-off wavelength around 14 μm at 80 K and a quantum efficiency slightly above 20%. The dark current density was of 4.6×10⁻² A/cm² at 80 K and a minority carrier lateral diffusion was evaluated through dark current measurements on different detector sizes. In addition, detector spectral response, its dark current-voltage characteristics and capacitance-voltage curve accompanied by electric field simulations were analyzed in order to determine the operating bias and the dark current regimes at different biases. Finally, dark current simulations were also performed to estimate a minority carrier lifetime by comparing experimental curves with simulated ones.
Źródło:
Opto-Electronics Review; 2020, 28, 3; 164--170
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technology and properties of low-pressure metalorganic vapour phase epitaxy grown InGaAs/AlInAs superlattice for quantum cascade laser applications
Autorzy:
Badura, M.
Bielak, K.
Ściana, B.
Radziewicz, D.
Pucicki, D.
Dawidowski, W.
Żelazna, K.
Kudrawiec, R.
Tłaczała, M.
Powiązania:
https://bibliotekanauki.pl/articles/173549.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
InGaAs
AlInAs
superlattice
metalorganic vapour phase epitaxy
MOVPE
quantum cascade laser
QCL
Opis:
Quantum cascade laser is one of the most sophisticated semiconductor devices. The active region of the quantum cascade laser consists of hundreds thin layers, thus the deposition precision is the most crucial. The main technique for the fabrication of quantum cascade laser structure is molecular beam epitaxy, however, the prevalence of metalorganic vapour phase epitaxy techniques in the fabrication of semiconductor structures causes a perpetual work on the improvement production of the entire quantum cascade laser structure by the metalorganic vapour phase epitaxy. The paper presents technological aspects connected with the metalorganic vapour phase epitaxy growth of InGaAs/AlInAs low-dimensional structures for quantum cascade laser active region emitting ~9.6 μm radiation. Epitaxial growth of superlattice made of InGaAs/AlInAs lattice matched to InP was conducted at the AIXTRON 3x2″ FT system. Optical and structural properties of such heterostructures were characterised by means of high resolution X-ray diffraction, photoluminescence, contactless electroreflectance and scanning electron microscope techniques. Epitaxial growth and possible solutions of structure improvements are discussed.
Źródło:
Optica Applicata; 2016, 46, 2; 241-248
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dark current behaviour of type-II superlattice longwave infrared photodetectors under proton irradiation
Autorzy:
Bataillon, Clara
Perez, Jean-Phillipe
Alchaar, Rodolphe
Michez, Alain
Gilard, Olivier
Saint-Pé, Olivier
Christol, Philippe
Powiązania:
https://bibliotekanauki.pl/articles/2204227.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
displacement damage dose
proton radiation
total ionizing dose
type-II superlattice photodetector
Opis:
In this work, the authors investigated the influence of proton-irradiation on the dark current of XBp longwave infrared InAs/GaSb type-II superlattice barrier detectors, showing a cutoff wavelength from 11 μm to 13 μm at 80 K. The proton irradiations were performed with 63 MeV protons and fluences up to 8∙10¹¹ H+/cm² on a type-II superlattice detector kept at cryogenic (100 K) or room temperature (300 K). The irradiation temperature of the detector is a key parameter influencing the effects of proton irradiation. The dark current density increases due to displacement damage dose effects and this increase is more important when the detector is proton-irradiated at room temperature rather than at cryogenic temperature.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144552
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electro-optical performance and anisotropic transport study of a Ga-free type-II superlattice barrier structure
Autorzy:
Bouschet, Maxime
Arounassalame, Vignesh
Ramiandrasoa, Anthony
Perez, Jean-Philippe
Péré-Laperne, Nicolas
Ribet-Mohamed, Isabelle
Christol, Philippe
Powiązania:
https://bibliotekanauki.pl/articles/2204222.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
infrared photodetector
type-II superlattice
barrier structure
Ga-free
transport
anisotropy
Opis:
In the past ten years, InAs/InAsSb type-II superlattice has emerged as a promising technology for high-temperature mid-wave infrared photodetector. Nevertheless, transport properties are still poorly understood in this type of material. In this paper, optical and electro-optical measurements have been realised on InAs/InAsSb type-II superlattice midwave infrared photodetectors. Quantum efficiency of 50% is measured at 150 K, on the front side illumination and simple pass configuration. Absorption measurement, as well as lifetime measurement are used to theoretically calculate the quantum efficiency thanks to Hovel’s equation. Diffusion length values have been extracted from this model ranging from 1.55 μm at 90 K to 7.44 μm at 200 K. Hole mobility values, deduced from both diffusion length and lifetime measurements, varied from 3.64 cm²/Vs at 90 K to 37.7 cm²/Vs at 200 K. The authors then discuss the hole diffusion length and mobility variations within temperature and try to identify the intrinsic transport mechanisms involved in the superlattice structure.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144549
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of low frequency noise of infrared photo-detectors with transimpedance detection system
Autorzy:
Ciura, Ł.
Kolek, A.
Gawron, W.
Kowalewski, A.
Stanaszek, D.
Powiązania:
https://bibliotekanauki.pl/articles/221094.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
1/f noise
infrared detectors
nBn structure
HgCdTe heterostructures
noise measurements
transimpedance detection system
type II InAs/GaSb superlattice
Opis:
The paper presents the method and results of low-frequency noise measurements of modern mid-wavelength infrared photodetectors. A type-II InAs/GaSb superlattice based detector with nBn barrier architecture is compared with a high operating temperature (HOT) heterojunction HgCdTe detector. All experiments were made in the range 1 Hz - 10 kHz at various temperatures by using a transimpedance detection system, which is examined in detail. The power spectral density of the nBn’s dark current noise includes Lorentzians with different time constants while the HgCdTe photodiode has more uniform 1/f - shaped spectra. For small bias, the low-frequency noise power spectra of both devices were found to scale linearly with bias voltage squared and were connected with the fluctuations of the leakage resistance. Leakage resistance noise defines the lower noise limit of a photodetector. Other dark current components give raise to the increase of low-frequency noise above this limit. For the same voltage biasing devices, the absolute noise power densities at 1 Hz in nBn are 1 to 2 orders of magnitude lower than in a MCT HgCdTe detector. In spite of this, low-frequency performance of the HgCdTe detector at ~ 230K is still better than that of InAs/GaSb superlattice nBn detector.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 461-472
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High performance type-II InAs/GaSb superlattice infrared photodetectors with a short cut-off wavelength
Autorzy:
Delmas, Marie
Ramos, David
Ivanov, Ruslan
Žurauskaitė, Laura
Evans, Dean
Rihtnesberg, David
Almqvist, Susanne
Becanovic, Smilja
Costard, Eric
Höglund, Linda
Powiązania:
https://bibliotekanauki.pl/articles/2204225.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
infrared detectors
short-wavelength infrared
InAs/GaSb superlattice
type-II superlattice
Opis:
This work investigates the potential of InAs/GaSb superlattice detectors for the shortwavelength infrared spectral band. A barrier detector structure was grown by molecular beam epitaxy and devices were fabricated using standard photolithography techniques. Optical and electrical characterisations were carried out and the current limitations were identified. The authors found that the short diffusion length of ~1.8 µm is currently limiting the quantum efficiency (double-pass, no anti-reflection coating) to 43% at 2.8 µm and 200 K. The dark current density is limited by the surface leakage current which shows generation-recombination and diffusion characters below and above 195 K, respectively. By fitting the size dependence of the dark current, the bulk values have been estimated to be 6.57·10ˉ⁶ A/cm² at 200 K and 2.31·10ˉ⁶ A/cm² at 250 K, which is only a factor of 4 and 2, respectively, above the Rule07.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144555
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The pecularities of structure and diffraction by mis fit mixed-layer nanotubes
Autorzy:
Figovsky, O.
Pashin, D.
Khalitov, Z.
Valeeva, D.
Chkanov, A.
Powiązania:
https://bibliotekanauki.pl/articles/411579.pdf
Data publikacji:
2012
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
nanorurki
karbowanie nanorurek
nanotube
goffered nanotube
superlattice
Opis:
The analysis of diffraction by separate mixed-layer goffered nanotube's lattice is offered. Two extreme cases of the large and small size of coherent scattering regions (CSR) in a radial direction are considered. The qualitative explanation of observed diffraction effects is given.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2012, 2; 7-14
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The growth and characterisation of type I GaSb/AlSb superlattice with a thin GaSb layer
Autorzy:
Fokt, Maciej
Jasik, Agata
Sankowska, Iwona
Mączko, Herbert S.
Paradowska, Karolina M.
Czuba, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/27315692.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
type I AlSb/GaSb superlattice
8-band k·p perturbation theory
nextnano simulations
AlSb layer degradation
Opis:
This paper presents results of the characterisation of type I GaSb/AlSb superlattices (SLs) with a thin GaSb layer and varying thicknesses of an AlSb layer. Nextnano software was utilized to obtain spectral dependence of absorption and energy band structure. A superlattice (SL) with an energy bandgap of ~ 1.0 eV and reduced mismatch value was selected for experimental investigation. SLs with single (sample A) and double (sample B) AlSb barriers and a single AlSb layer (sample C) were fabricated using molecular beam epitaxy (MBE). Optical microscopy, high-resolution X-ray diffractometry, and photoluminescence were utilized for structural and optical characterisation. The presence of satellite and interference peaks in diffraction curves confirms the high crystal quality of superlattices. Photoluminescence signal associated with the superlattice was observed only for sample B and contained three low-intensity peaks: 1.03, 1.18, and 1.25 eV. The first peak was identified as the value of the energy bandgap of the SL. Other two peaks are related to optical transitions between defect states located at the interface between the SL and the top AlSb barrier. The time-dependent changes observed in the spectral characteristics are due to a modification of the SL/AlSb interface caused by the oxidation and hydroxylation of the AlSb layer.
Źródło:
Opto-Electronics Review; 2023, 31, 4; art. no. e147912
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Barrier in the valence band in the nBn detector with an active layer from the type-II superlattice
Autorzy:
Kopytko, Małgorzata
Gomółka, Emilia
Manyk, Tetiana
Michalczewski, Krystian
Kubiszyn, Łukasz
Rutkowski, Jaroslaw
Martyniuk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1818207.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
infrared detector
T2SLs
superlattice
III-V materials
I-V characteristics
Opis:
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.
Źródło:
Opto-Electronics Review; 2021, 29, 1; 1--4
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Barrier in the valence band in the nBn detector with an active layer from the type-II superlattice
Autorzy:
Kopytko, Małgorzata
Gomółka, Emilia
Manyk, Tetiana
Michalczewski, Krystian
Kubiszyn, Łukasz
Rutkowski, Jaroslaw
Martyniuk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1818204.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
infrared detector
T2SLs
superlattice
III-V materials
I-V characteristics
Opis:
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.
Źródło:
Opto-Electronics Review; 2021, 29, 1; 1--4
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and performance of dual-band MWIR/LWIR focal plane arrays based on a type-II superlattice nBn structure
Autorzy:
Lee, Hyun-Jin
Eom, Jun Ho
Jung, Hyun Chul
Kang, Ko-Ku
Ryu, Seong Min
Jang, Ahreum
Kim, Jong Gi
Kim, Young Ho
Jung, Han
Kim, Sun Ho
Choi, Jong Hwa
Powiązania:
https://bibliotekanauki.pl/articles/2204217.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
InAs/GaSb type-II superlattice
dualband detector
dark current
spectral quantum efficiency
noise equivalent temperature difference
Opis:
Dual-band infrared detector, which acquires more image information than single-band detectors, has excellent detection, recognition, and identification capabilities. The dual-band detector can have two bumps to connect with each absorber layer, but it is difficult to implement small pitch focal plane arrays and its fabrication process is complicated. Therefore, the most effective way for a dual-band detector is to acquire each band by biasselectable with one bump. To aim this, a dual-band MWIR/LWIR detector based on an InAs/GaSb type-II superlattice nBn structure was designed and its performance was evaluated in this work. Since two absorber layers were separated by the barrier layer, each band can be detected by bias-selectable with one bump. The fabricated dual-band device exhibited the dark current and spectral response characteristics of MWIR and LWIR bands under negative and positive bias, respectively. Spectral crosstalk that is a major issue in dualband detectors was also improved. Finally, a 20 µm pitch 640 x 512 dual-band detector was fabricated, and both MWIR and LWIR images exhibited an average noise equivalent temperature difference of 30 mK or less at 80 K.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144560
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth and characterisation of LWIR T2SL on (100)-, (211)- and (311)-oriented GaSb substrates
Autorzy:
Lubyshev, Dmitri
Fastenau, Joel M.
Kattner, Michael
Frey, Philip
Nelson, Scott A.
Flick, Ryan
Wu, Ying
Liu, Amy W. K.
Szymanski, Dennis E.
Martinez, Becky
Furlong, Mark J.
Dennis, Richard
Bundas, Jason
Sundaram, Mani
Powiązania:
https://bibliotekanauki.pl/articles/2204213.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
focal plane arrays
InAs/InAsSb
photodetectors
long wavelength infrared type-II superlattice
metamorphic buffers
superlattice period reduction
Opis:
Ga-free InAs/InAsSb type-II superlattice structures grown on GaSb substrates have demonstrated high performance for mid-wave infrared applications. However, realisation of long wavelength infrared photodetectors based on this material system still presents challenges, especially in terms of reduced quantum efficiency. This reduction is due, in part, to the increased type-II superlattice period required to attain longer wavelengths, as thicker periods decrease the wave-function overlap for the spatially separated quantum wells. One way to improve long wavelength infrared performance is to modify the type-II superlattice designs with a shorter superlattice period for a given wavelength, thereby increasing the wave-function overlap and the resulting optical absorption. Long wavelength infrared epitaxial structures with reduced periods have been realised by shifting the lattice constant of the type-II superlattice from GaSb to AlSb. Alternatively, epitaxial growth on substrates with orientations different than the traditional (100) surface presents another way for superlattice period reduction. In this work, the authors evaluate the performance of long wavelength infrared type-II superlattice detectors grown by molecular beam epitaxy using two different approaches to reduce the superlattice period: first, a metamorphic buffer to target the AlSb lattice parameter, and second, structures lattices matched to GaSb using substrates with different orientations. The use of the metamorphic buffer enabled a ~30% reduction in the superlattice period compared to reference baseline structures, maintaining a high quantum efficiency, but with the elevated dark current related to defects generated in the metamorphic buffer. Red-shift in a cut-off wavelength obtained from growths on highindex substrates offers a potential path to improve the infrared photodetector characteristics. Focal plane arrays were fabricated on (100), (311)A- and (211)B-oriented structures to compare the performance of each approach.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144568
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum simulations of band-to-band tunnelling in a type-II broken-gap superlattice diode
Autorzy:
Makowiec, Marcin
Kolek, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2204215.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
type-II superlattice
broken-gap superlattice diode
band-to-band tunnelling
quantum transport
nonequilibrium Green’s function
twoband Hamiltonian
Opis:
In recent years, type-II superlattice-based devices have completed the offer of the electronic industry in many areas of applications. Photodetection is one of them, especially in the midinfrared wavelength range. It is due to the unique feature of a superlattice material, which is a tuneable bandgap. It is also believed that the dark current of superlattice-based photodetectors is strongly suppressed due to the suppression of the band-to-band tunnelling current in a superlattice material. This argument relies, however, on a semi-classical approach that treats superlattice as a bulk material with effective parameters extracted from the k·p analysis. In the paper, a superlattice device is analysed on a quantum level: the nonequilibrium Green’s function method is applied to the two-band Hamiltonian of the InAs/GaSb superlattice p-i-n diode. The analysis concentrates on the band-to-band tunnelling with the aim to validate the correctness of a semi-classical description of the phenomenon. The results of calculations reveal that in a superlattice diode, the inter-band tunnelling occurs only for certain values of energy and in-plane momentum, for which electronic and hole sub-bands cross. The transitions occurring for vanishing in-plane momentum produce resonances in the current-voltage characteristics - the feature which was reported in a few experimental observations. This scenario is quite different from that occurring in bulk materials, where there is a range of energy-momentum pairs for which the band-to-band tunnelling takes place, and so current-voltage characteristics are free from any resonances. However, simulations show that, while not justified for a detailed analysis, the semi-classical description can be applied to superlattice-based devices for an ‘order of magnitude’ estimation of the band-to-band tunnelling current.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144558
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 22

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