Temat: type-II superlattice

Skocz do pozycji: 1.

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
Tematy:: infrared detectors
short-wavelength infrared
InAs/GaSb superlattice
type-II superlattice; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204225.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Two-step etch in n-on-p type-II superlattices for surface leakage reduction in mid-wave infrared megapixel detectors
Autorzy:: Ramos, David
Delmas, Marie
Ivanov, Ruslan
Žurauskaitė, Laura
Evans, Dean
Almqvist, Susanne
Becanovic, Smilja
Hellström, Per-Erik
Costard, Eric
Höglund, Linda
Tematy:: infrared detector
surface leakage
type-II superlattice
megapixel
n-on-p; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204214.pdf Link otwiera się w nowym oknie
Opis:: This work investigates the potential of p-type InAs/GaSb superlattice for the fabrication of full mid-wave megapixel detectors with n-on-p polarity. A significantly higher surface leakage is observed in deep-etched n-on-p photodiodes compared to p-on-n diodes. Shallowetch and two-etch-step pixel geometry are demonstrated to mitigate the surface leakage on devices down to 10 μm with n-on-p polarity. A lateral diffusion length of 16 μm is extracted from the shallow etched pixels, which indicates that cross talk could be a major problem in small pitch arrays. Therefore, the two-etch-step process is used in the fabrication of 1280 × 1024 arrays with a 7.5 μm pitch, and a potential operating temperature up to 100 K is demonstrated.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 3.

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
Tematy:: infrared photodetector
type-II superlattice
barrier structure
Ga-free
transport
anisotropy; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204222.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 4.

Tytuł:: InAs/InAsSb superlattice infrared detectors
Autorzy:: Ting, David Z.
Soibel, Alexander
Khoshakhlagh, Arezou
Keo, Sam A.
Rafol, Sir B.
Fisher, Anita M.
Hill, Cory J.
Pepper, Brian J.
Maruyama, Yuki
Gunapala, Sarath D.
Tematy:: infrared detector
type-II superlattice
InAs/InAsSb
complementary barrier infrared detectors
strained layer superlattice; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204211.pdf Link otwiera się w nowym oknie
Opis:: Mid-wavelength infrared detectors and focal plane array based on n-type InAs/InAsSb type- II strained layer superlattice absorbers have achieved excellent performance. In the long and very long wavelength infrared, however, n-type InAs/InAsSb type-II strained layer superlattice detectors are limited by their relatively small absorption coefficients and short growth-direction hole diffusion lengths, and consequently have only been able to achieve modest level of quantum efficiency. The authors present an overview of their progress in exploring complementary barrier infrared detectors that contain p-type InAs/InAsSb type-II strained layer superlattice absorbers for quantum efficiency enhancement. The authors describe some representative results, and also provide additional references for more indepth discussions. Results on InAs/InAsSb type-II strained layer superlattice focal plane arrays for potential NASA applications are also briefly discussed.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 5.

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
Tematy:: displacement damage dose
proton radiation
total ionizing dose
type-II superlattice photodetector; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204227.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

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
Tematy:: focal plane arrays
InAs/InAsSb
photodetectors
long wavelength infrared type-II superlattice
metamorphic buffers
superlattice period reduction; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204213.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 7.

Tytuł:: Quantum simulations of band-to-band tunnelling in a type-II broken-gap superlattice diode
Autorzy:: Makowiec, Marcin
Kolek, Andrzej
Tematy:: type-II superlattice
broken-gap superlattice diode
band-to-band tunnelling
quantum transport
nonequilibrium Green’s function
twoband Hamiltonian; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204215.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 8.

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
Tematy:: InAs/GaSb type-II superlattice
dualband detector
dark current
spectral quantum efficiency
noise equivalent temperature difference; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204217.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Long wavelength type-II superlattice barrier infrared detector for CubeSat hyperspectral thermal imager
Autorzy:: Rafol, Sir B.
Gunapala, Sarath D.
Ting, David Z.
Soibel, Alexander
Khoshakhlagh, Arezou
Keo, Sam A.
Pepper, Brian J.
Hill, Cory J.
Maruyama, Yuki
Fisher, Anita M.
Sood, Ashok
Zeller, John
Wright, Robert
Lucey, Paul
Nunes, Miguel
Flynn, Luke
Babu, Sachidananda
Ghuman, Parminder
Tematy:: type-II superlattice
focal plane array
infrared detector
quantum efficiency
noise equivalent difference temperature
dark current density
anti-reflective coating; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2204204.pdf Link otwiera się w nowym oknie
Opis:: The hyperspectral thermal imaging instrument for technology demonstration funded by NASA’s Earth Science Technology Office under the In-Space Validation of Earth Science Technologies program requires focal plane array with reasonably good performance at a low cost. The instrument is designed to fit in a 6U CubeSat platform for a low-Earth orbit. It will collect data on hydrological parameters and Earth surface temperature for agricultural remote sensing. The long wavelength infrared type-II strain layer superlattices barrier infrared detector focal plane array is chosen for this mission. With the driving requirement dictated by the power consumption of the cryocooler and signal-noise-ratio, cut-off wavelengths and dark current are utilized to model instrument operating temperature. Many focal plane arrays are fabricated and characterised, and the best performing focal plane array that fulfils the requirements is selected. The spectral band, dark current and 8-9.4 μm pass band quantum efficiency of the candidate focal plane array are: 8-10.7 μm, 2.1∙10ˉ⁵ A/cm², and 47%, respectively. The corresponding noise equivalent difference temperature and operability are 30 mK and 99.7%, respectively. Anti-reflective coating is deposited on the focal plane array surface to enhance the quantum efficiency and to reduce the interference pattern due to an absorption layer parallel surfaces cladding material.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The use of one-component plasma in the ICP-RIE etching process of periodic structures for applications in photodetector arrays
Autorzy:: Różycka, Marta
Jasik, Agata
Kozłowski, Paweł
Bracha, Krzysztof
Ratajczak, Jacek
Wierzbicka-Miernik, Anna
Tematy:: ICP-RIE
dry etching
type II InAs/GaSb superlattice
BCl3; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/58973688.pdf Link otwiera się w nowym oknie
Opis:: The paper presents the effect of ICP-RIE etching time using one-component plasma on various parameters of an InAs/GaSb type II superlattice matrix. In the studies, two samples used at different BCl3 gas flow rates were compared and it was found that using a lower flow rate of 7 sccm results in obtaining a smoother sidewall morphology. Next, five periodic mesa-shaped structures were etched under identical conditions, but using a different time. The results indicated that the ICP-RIE method using a BCl3 flow rate of 7 sccm, ICP:RIE power ratio of 300W:270W allowed the ICP:RIE formation of a periodic mesa-shaped structure with smooth and perpendicular sidewalls.
Dostawca treści:: Biblioteka Nauki

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