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Content available Review of photodetectors characterization methods
EN
The review includes results of analyses and research aimed at standardizing the concepts and measurement procedures associated with photodetector parameters. Photodetectors are key components that ensure the conversion of incoming optical radiation into an electrical signal in a wide variety of sophisticated optoelectronic systems and everyday devices, such as smartwatches and systems that measure the composition of the Martian atmosphere. Semiconductor detectors are presented, and they play a major role due to their excellent optical and electrical parameters as well as physical parameters, stability, and long mean time to failure. As their performance depends on the manufacturing technology and internal architecture, different types of photodetectors are described first. The following parts of the article concern metrological aspects related to their characterization. All the basic parameters have been defined, which are useful both for their users and their developers. This allows for the verification of photodetectors’ workmanship quality, the capabilities of a given technology, and, above all, suitability for a specific application and the performance of the final optoelectronic system. Experimentally validated meteorological models and equivalent diagrams, which are necessary for the correct analysis of parameter measurements, are also presented. The current state of knowledge presented in recognized scientific papers and the results of the authors’ works are described as well.
PL
Artykuł dotyczy wybranych wyników prac badawczo-rozwojowych realizowanych w Zespole Detekcji Sygnałów Optycznych IOE WAT. Prace te dotyczą głównie fotoodbiorników na różne zakresy widmowe, ultraczułych analizatorów gazów do wykrywania materiałów wybuchowych i biomarkerów chorób w ludzkim oddechu oraz bezpiecznych łączy laserowych w otwartej przestrzeni. W pracy opisano przykładowe układy detekcji promieniowania optycznego z zakresu od ultrafioletu do dalszej podczerwieni, które powstały w ramach prac statutowych i projektów badawczo-rozwojowych. Szczególną uwagę zwrócono na aspekty aplikacyjne uzyskanych wyników wskazując jednocześnie właściwości technologii, dla których zostały one zaprojektowane.
EN
The article presents a brief description of research and development works carried out by Group of Optical Signal Detection at the Institute of Optoelectronics, MUT. These activities mainly concern the construction of photoreceivers operated in various spectral ranges, ultra-sensitive gas analyzers for detection of explosives and diseases biomarkers in human breath, and free space optical data link. Some exemplary detection systems of radiation spectra from ultraviolet to longer infrared, which were designed as a part of academic works or R&D projects, are described. Some practical aspects of these results for some optoelectronic technologies are discussed.
3
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.
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.
EN
Antimony is a promising material for the fabrication of photodetectors. This study deals with the growth of a photosensitive thin film by the physical vapor deposition (PVD) of antimony onto mica surface in a furnace tube. The geometry of the grown structures was studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and elemental diffraction analysis. XRD peaks of the antimony film grown on mica mostly matched with JCPDF Card. The formation of rhombohedral crystal structures in the film was further confirmed by SEM micrographs and chemical composition analysis. The Hall measurements revealed good electrical conductivity of the film with bulk carrier concentration of the order of 1022 Ω·cm-3 and mobility of 9.034 cm2/Vs. The grown film was successfully tested for radiation detection. The photoresponse of the film was evaluated using its current-voltage characteristics. These investigations revealed that the photosensitivity of the antimony film was 20 times higher than that of crystalline germanium.
PL
W artykule przedstawiono wyniki prac zrealizowanych w laboratorium detekcji sygnałów optycznych Instytutu Optoelektroniki WAT. Dotyczą one badań, które były realizowane w ramach projektów naukowych, jak również współpracy z innymi zespołami naukowymi. Przedstawiono rezultaty parametryzacji układów detekcji pracujących w różnych zakresach widma promieniowania optycznego z uwzględnieniem ich praktycznego zastosowania.
EN
The article presents selected research carried out at the Laboratory of Optical Detection Systems, IOE MUT. There were underlined works related to investigation of different generations of detectors and detection modules. The scope of research results from the framework of science projects, as well as from other team’s cooperation. Descriptions concern the detection systems characterization at different spectra of optical radiation taking into consideration their dedicated applications.
EN
This paper analyzes some advantages of Silicon-on-Insulator (SOI) based photodetectors for low light imaging. It shows that SOI based sensors not only solve the bulk carriers problem, it can also act as a very selective spectral filter by acting as a resonant cavity, which is useful in application with a very narrow spectrum of interest, such as bioluminescence imaging. The SOI implementation of a switching photodetector based with an hybrid MOS-PN structure is presented and its advantages in terms of dark current minimization and SNR improvement highlighted.
EN
In this paper an analysis of tendencies of Ge on Si quantum dots nanoheterostructures’ usage in different optoelectronic devices such as, for example, solar cells and photodetectors of visible and infra-red regions is carried out; a complex mathematical model for calculation of dependency on growth conditions of self-organized quantum dots of Ge on Si grown using the method of molecular beam epitaxy parameters is described. Ways of segregation effect and underlying layers’ influence are considered. It is shown that for realization of good device characteristics quantum dots should have high density, small sizes, uniformity, and narrow size distribution function. The desirable parameters of arrays of square and rectangular quantum dots for device application are attainable under certain growth conditions.
EN
The paper reports on the medium wavelength infrared (MWIR) unipolar barrier infrared detector (UBIRD) nBn/B-n type (n-type barrier) HgCdTe detector’s photoelectrical performance. The UBIRD nBn/B-n type HgCdTe detector was modelled using commercially available software APSYS. Detailed analysis of the detector’s performance (such as dark current, photocurrent, responsivity, and detectivity) versus bias voltage, operating temperatures, and structural parameters (cap, barrier, and absorber’s doping as well as cap and barrier compositions) were performed pointing out optimal working conditions. Both conduction and valence band alignments of the HgCdTe nBn/B-n type detector structure was simulated stressing their importance on detectors performance. It was shown that higher operation temperature (HOT) conditions achieved by commonly used thermoelectric (TE) coolers allow to obtain detectivities of D* = (3-10)×109 cmHz1/2/W at T = 200 K for detectors with cut-off wavelength of 5.2 ?m The differential resistance area product of RA = 0.15-0.4 cm2 at T = 230 K for bias voltage V = 50 mV was estimated. Finally, the state of the art of UBIRD HgCdTe nBn/B-n type detector performance was compared to InAs/GaSb/B-Al0.2Ga0.8Sb T2SLs nBn detector, InAs/GaSb T2SLs PIN and the HOT HgCdTe bulk photodiodes’ operated at near-room temperature (T = 230 K). It was shown that the RA product of the MWIR UBIRD nBn/B-n type HgCdTe detector can reach a comparable level to the state of the art of the HgCdTe HOT bulk photodiodes and two types of type-II superlattice detectors: PIN photodiodes and nBn detectors.
PL
Detektory promieniowania podczerwonego z wąską przerwą energetyczną wymagają chłodzenia celem ograniczenia prądów ciemnych generowanych w strukturze detekcyjnej wśród których najważniejszymi są: procesy generacyjno - rekombinacyjne Shockley-Read-Halla i procesy Augera. Obecnie, zwiekszenie temperatury pracy urządzeń detekcyjnych bez ograniczenia ich osiągów jest głównym celem wielu zespołów badawczych. Procesy generacyjno - rekombinacyjne Augera można ograniczyc poprzez budowę urządzęń detekcyjnych z supersieci II rodzaju (type II superlattice - T2SLs) z związków AIIIBV należących do rodziny 6.1 L. Implementacja barier do struktur detekcyjnych pozwala zredukować niekorzystny wpły procesów Shockley-Read-Halla. Ograniczenie wpływu obu mechanizmów pozwoli zwiększyć temperaturę pracy detektora. Artykuł przedstawia osiągi unipolarnych detektorów nBn z T2SLs InAs/GaSb/B- AI₀.₂Ga₀.₈Sb i HgCdTe oraz ich potencjalne możliwości w rozwoju detektorów promieniowania podczerwonego.
EN
The narrow band gap infrared detectors require cryogenic cooling to suppress dark current, which is typically limited by Shockley-Read-Hall (SRH) and Auger generation-recombination processes. Currently, increasing the operating temperature of the infrared detection systems without sacrificing its performance remains to be a crucial objective of the research groups. Intrinsic Auger thermal generation recombination process could be controlled by implementation of the type II superlattices (T2SLs) AIIIBV 6.1 L family to the detectors architecture while extrinsic SRH process could be suppressed by the barrier's incorporation into detector's structure respectively. Both SHR and Auger suppression lead to increase of the device's operating temperature. The paper reports on the unipolar barrier infrared detector (UBIRD) medium wavelength infrared (MWIR) HgCdTe nBn/B-n type and T2SLs nBn lnAs/GaSb/B-AI₀.₂Ga₀.₈Sb detector's photoelectrical performance and their potential possibilities in the field of infrared detectors development.
EN
Recent efforts to improve the performance of type II InAs/GaSb superlattice photodiodes and focal plane arrays (FPA) have been reviewed. The theoretical bandstructure models have been discussed first. A review of recent developments in growth and characterization techniques is given. The efforts to improve the performance of MWIR photodiodes and focal plane arrays (FPAs) have been reviewed and the latest results have been reported. It is shown that these improvements has resulted in background limited performance (BLIP) of single element photodiodes up to 180 K. FPA shows a constant noise equivalent temperature difference (NEDT) of 11 mK up to 120 K and it shows human body imaging up to 170 K.
PL
Niechłodzone detektory podczerwieni z HgCdTe to jeden z niewielu produktów optoelektronicznych produkowanych obecnie w Polsce i eksportowanych do wielu krajów świata. Przyrządy te znajdują zastosowania praktyczne w nowoczesnej aparaturze naukowej i medycznej, w przemyśle, ochronie środowiska naturalnego, technice wojskowej. Artykuł prezentuje obecny stan rozwoju niechłodzonych detektorów podczerwieni w Polsce.
EN
Uncooled infrared photodetectors from HgCdTe are one of few optoelectronic products manufactured currently in Poland and exported to many countries worldwide. The devices have found important applications for scientific and medical instruments, in industry, environment protection, and military technique. The paper presents the state-of-art in the field of uncooled photodetectors from HgCdTe in Poland.
PL
Praca pokazuje zasady projektowania i właściwości detektorów podczerwieni dla szerokopasmowych modułów detekcyjnych przeznaczonych dla otwartych łączy optoelektronicznych. Są to heterostrukturalne fotodetektory długofalowego (8...12 µm) promieniowania podczerwonego pracujące bez chłodzenia kriogenicznego. Podstawą konstrukcji fotodetektorów są złożone heterostruktury HgCdTe wytwarzane metodą MOCVD.
EN
Long wavelength infrared photodetectors from HgCdTe for the second generation free-space optical links are reported. The photodetectors are based on optically immersed photodiodes operating with Peltier coolers. The photodiodes are based on HgCdTe heterostructure. The devices have been grown using Metalorganic Chemical Vapor Deposition (MOCVD).
PL
Skojarzenie fotoniki z technologią opartą na stosowaniu krzemu wydawało się do niedawna niedościgłą utopią, choć było oczywiste, że przyniosłoby w efekcie ogromne korzyści zarówno mikroelektronice, jak i samej fotonice. Wytrwałe badania doprowadziły jednak w ostatnich latach do radykalnej zmiany w opinii na temat perspektyw takiego skojarzenia. W artykule omówiono podstawowe podzespoły fotoniczne, w tym źródła światła, modulatory i fotodedektory, wytwarzane z krzemu pod kątem zastosowań przede wszystkim w układach połączeń optycznych prze­znaczonych do komunikacji między i wewnątrz komputerów.
EN
To combine photonics with the silicon-based technology seemed in a not distant past beyond the reach, although it has been clear that it would be beneficiary for both microelectronics and photonics. However, persistent research has lead in recent years to a radical change in opinions on that matter. In this paper silicon based photonic devices are discussed including light sources, modulators and photodetectors, all essential for optical interconnects between - and within computers.
15
Content available remote Photosensitive macroporous silicon based structures
EN
Macroporous silicon prepared in n-type silicon have been used for a photosensitive device formation. Boron-doped spun-on layer was applied for p+ emitter formation of the devices. The obtained structures were investigated by AFM and electron microscopy, photosensitivity and the photocurrent spectra were measured to evaluate the influence of porous layer and boron diffusion conditions. Unusually fast boron diffusion through the porous emitter was investigated, stipulating the p+ -n junction to be positioned 2.5 µm deeper the pores bottom. This effect was explained by a presence of local electric fields, caused by tensions present at the border between PS layer and crystalline substrate and by possible deeper nanoporous structure, what was partially proofed by AFM.
EN
During the past decade, group III-Nitride wide bandgap semiconductors have become the focus of extremely intensive reearch because of their exceptional physical properties and their high potential for use in countless numbers of applications. Nearly all aspects have been investigated, from the fundamental physical understanding of these materials to the development of the fabrication technology and demonstration of commercial devices. The purpose of this paper is to review the physical properties of III-Nitrides, their areas of application, the current status of the material technology (AlN, AlGaN, GaN, GaInN) including synthesis and processing. The state-of-the-art of III-Nitride material quality, as well as the devices which have been demonstrated, including electronic devices, AlxGa₁-xN ultraviolet photoconductors, ultraviolet photodiodes, visible light emitting diodes (LEDs) and ultraviolet - blue laser diodes, will also be presented.
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