Wyniki wyszukiwania - Biblioteka Nauki

1

Role of nitrogen in carrier confinement potential engineering and optical properties of GaAs-based quantum wells heterostructures

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Pucicki D. , Bielak K. , Dawidowski W. , Ściana B. , Tłaczała M.

Optica Applicata

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2016

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tom Vol. 46, nr 2

255--263

EN

In this work, the authors present the results of optical characterization of GaAs-based multiple quantum well heterostructures, together with energy band structure analysis. The optical properties were investigated by applying photoluminescence spectroscopy. Structures with GaInNAs, GaInAs and GaNAs multiple quantum wells emitting around 1 μm, grown by atmospheric pressure metalorganic vapor phase epitaxy, were compared in this work. The role of nitrogen in quantum well carriers confinement potential was analysed. The photoluminescence intensities of the samples were correlated with the analysis of energy band structures and the overlaps of the carriers’ wave functions. In addition, the main carrier activation energies were estimated based on photoluminescence temperature dependence and the Arrhenius plots analysis. It was deduced that the thermal photoluminescence decay is most probably related to the escape of electrons whereas the holes, independently of the potential well depth, are additionally confined by the local inhomogeneities or by the Coulomb interaction with the confined electrons.

2

GaInNAs quantum-well vertical-cavity surface-emitting lasers emitting at 2.33 μm

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Piskorski Ł. , Sarzała R. P.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2013

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tom Vol. 61, nr 3

737--744

EN

In the present paper, the comprehensive fully self-consistent optical-electrical-thermal-recombination model is used to determine the optimal structure of the possible GaInNAs quantum-well (QW) tunnel-junction (TJ) vertical-cavity surface-emitting lasers (VCSELs) with single-fundamental-mode operation at 2.33 μm wavelength suited for carbon monoxide sensing applications. From among various considered structures, the diode laser with 4-μm TJ and two 6-nm Ga0.15In0.85N0.015As0.985/Ga0.327In0.673As0.71P0.29 QWs has the lowest threshold current and seems to be optimal for the above applications. Higher threshold currents are obtained for Ga0.15In0.85N0.015As0.985/Al0.138 -Ga0.332In0.530As QW structures but the latter can be grown in reactors without P source which are used for fabrication of GaAs-based devices. Both the modelled VCSELs offer a very promising room temperature continuous wave performance and may represent an alternative choice to GaSb-based lasers.

3

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

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Pucicki D.

Materials Science Poland

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2017

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tom 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.

4

AP-MOVPE Technology and Characterization of InGaAsN p-i-n Subcell for InGaAsN/GaAs Tandem Solar Cell

88%

Dawidowski W. , Ściana B. , Zborowska-Lindert I. , Mikolásek M. , Latkowska M. , Radziewicz D. , Pucicki D. , Bielak K. , Badura M. , Kováč J. , Tłaczała M.

International Journal of Electronics and Telecommunications

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2014

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tom Vol. 60, No. 2

151-156

EN

Tandem (two p-n junctions connected by tunnel junction) and multijunction solar cells (MJSCs) based on AIIIBV semiconductor compounds and alloys are the most effective photovoltaic devices. Record efficiency of the MJSCs exceeds 44% under concentrated sunlight. Individual subcells connected in series by tunnel junctions are crucial components of these devices. In this paper we present atmospheric pressure metal organic vapour phase epitaxy (AP-MOVPE) of InGaAsN based subcell for InGaAsN/GaAs tandem solar cell. The parameters of epitaxial structure (optical and electrical), fabrication process of the test solar cell devices and current-voltage (J-V) characteristics are presented and discussed.

5

InNAs : a new optoelectronic material for mid-infrared applications

75%

Osiński M.

Opto-Electronics Review

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2003

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tom Vol. 11, No. 4

321-326

EN

The InNx As1-x alloy is a very promissing, although so far almost completely unexplored, novel material for mid-IR emitters and detectors. InNAs/GaAs multiple quantum wells were grown by MOCVD on GaAs substrates, using dimenthylhydrazine (DMHy) as nitrogen precursor. The crystalline quality and solid phase composition were evaluated by high-resolution x-ray diffraction. The nitrogen content in InNAs wells was determined to be 18%. The measurements indicate high quality of quantum-well structures. The peak photoluminescence emission wavelengths of ~6.5 um at 30 K and ~7.2 um at 193 K are the longest reported so far for dilute nitride semiconductors.

6

Characterization of deep-level defects in GaNAs/GaAs heterostructures grown by APMOVPE

75%

Gelczuk Ł. , Dąbrowska-Szata M. , Ściana B. , Pucicki D. , Radziewicz D. , Kopalko K. , Tłaczała M.

Materials Science Poland

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2016

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tom Vol. 34, No. 4

726--734

EN

Conventional deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS techniques were used to study electrical properties of deep-level defects in dilute GaNAs epitaxial layers grown by atmospheric-pressure metalorganic vapourphase epitaxy (APMOVPE) on the GaAs substrate. Three samples with nitrogen concentrations of 1.2 %, 1.6 % and 2.7 % were investigated. In DLTS and LDLTS spectra of the samples, four predominant electron traps were observed. On the basis of the obtained electrical parameters and previously published results, one of the traps was associated with N-related complex defects, while the other traps with common GaAs-like native defects and impurities, called EL6, EL3 and EL2.

7

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

75%

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

Materials Science Poland

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2013

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tom 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).

8

Parametry detektorów MSM wykorzystujących heterostruktury GaAsN/GaAs i MQW InGaAsN/GaAs

63%

Zborowska-Lindert I. , Ściana B. , Pucicki D. , Radziewicz D. , Boratyński B. , Tłaczała M.

Elektronika : konstrukcje, technologie, zastosowania

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2012

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tom Vol. 53, nr 2

52-54

PL

W artykule przedstawione zostały parametry fotodetektorów MSM wykonanych na warstwach czynnych GaAsN/GaAs i MQW InGaAsN/GaAs. Wszystkie warstwy czynne optycznie wykonane zostały w technologii epitaksji MOVPE. W warstwach GaAsN/GaAs struktura czynna GaAsN miała grubość 100...330 nm, a zawartość atomów azotu mieściła się w zakresie 0,85...2,2%. Struktury MQW InGaAsN/GaAs stanowiły trzy studnie InGa-AsN o grubości 15 nm i zawartości 11% indu rozdzielone barierami GaAs o grubości 30 nm. W pracy przedstawiono charakterystyki prądowo-napięciowe detektorów MSM bez i z oświetleniem, co pozwala określić podstawowe parametry wykonanych fotodetektorów. Z uzyskanych wyników widać bardzo wyraźny wpływ składu materiałowego wykonanych heterostruktur na fotoprąd i czułość wykonanych fotodetektorów MSM.

EN

In this paper the comparison of GaAsN/GaAs and InGaAsN/GaAs MSM photodetectors has been presented. All of the devices were made by MOVPE technology. The GaAsN/GaAs MSM devices were made on undoped GaAsN layers with concentration of nitrogen varied from 0.85...2.2%. The thickness of these layers was from 100...330 nm. The InGaAsN/GaAs active layer for MSM detectors consisted of triple InGaAsN MQW with 11% of indium in 15 nm thick QWs layers and 30 nm thick GaAs barrier layers. The dark and illuminated l-V characteristics of the designed devices were presented. The photoresponse characteristics have shown a strong influence of material composition on the MSM photocurrent for both GaAsN/GaAs and InGaAsN/GaAs heterostructures.

9

Zastosowanie InGaAsN w konstrukcji ogniwa słonecznego p-i-n

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Dawidowski W. , Ściana B. , Zborowska-Lindert I. , Pucicki D. , Radziewicz D. , Bielak K. , Latkowska M. , Kovac J. , Tłaczała M.

Elektronika : konstrukcje, technologie, zastosowania

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2012

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tom Vol. 53, nr 7

90-92

PL

Wzrost światowego zapotrzebowania na energię elektryczną wymusza rozwój badań w zakresie alternatywnych źródeł energii. Fotowoltaika wydaje się być perspektywicznym i nieszkodliwym dla środowiska sposobem konwersji promieniowania słonecznego na sygnał elektryczny. Obok powszechnych już ogniw i modułów krzemowych aktualnie badane są wysokosprawne, wielozłączowe ogniwa bazujące ma materiałach AIIIBV. W niniejszej pracy przedstawiono wyniki dotyczące zastosowania poczwórnych związków półprzewodnikowych InGaAsN w konstrukcji ogniwa słonecznego p-i-n.

EN

The worldwide increase of electric power consumption forces the development of alternative sources of energy. Photovoltaics seems to be a promising and harmless to the natural environment method of producing electrical power. Besides silicon cells and panels, present researches are focused on high efficiency and multijunction solar cells based on AIIIBV semiconductors. This paper presents the results of application of the new InGaAsN semiconductor compounds in the p-i-n solar cell construction.

10

Lasery z obszarami czynnymi z rozcieńczonych azotków wytworzone na podłożu InP emitujące w zakresie średniej podczerwieni

63%

Sarzała R. P. , Szczerbiak P. , Kudrawiec R.

Elektronika : konstrukcje, technologie, zastosowania

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2011

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tom Vol. 52, nr 10

82-84

PL

W pracy przedstawiono wyniki badań dotyczące możliwości wytworzenia laserów złączowych emitujących w zakresie 2...3,5 μm powstałych na bazie technologii fosforkowej. Obszary czynne tych laserów stanowią tzw. rozcieńczone azotki (w szczególności związek GaInNAs) dopasowane sieciowo do podłoża InP. Jak pokazują wyniki wstępnych badań tak wykonane emitery światła spójnego mogą stanowić poważną alternatywę dla obecnie stosowanej technologii antymonkowej. Zaprojektowane i zamodelowane numerycznie obszary czynne laserów wykazywały w podanym obszarze na tyle duże wzmocnienie materiałowe, że na ich bazie można myśleć nie tylko o wytworzeniu laserów o emisji krawędziowej ale i laserów typu VCSEL.

EN

In the present paper, results of our investigations concerning possible manufacturing of InP-based diode lasers emitting the 2...3.5 μm radiation are presented. Their active regions are produced from dilute nitrides (from GaInNAs in particular) lattice matched to the InP substrate. According to initial results of our investigations, the above koherent light emitters may become a serious alternative for currently used antimony technology. Computer simulations of their performance confirm such a high optical gain within their active regions that they may be used not only to produce edge-emitting lasers but vertical-cavity surface-emitting lasers as well.

11

Influence of the AP MOVPE process conditions on InGaAsN/GaAs MQW MSM photodetectors parameters

51%

Ściana B. , Zborowska-Lindert I. , Radziewicz D. , Pucicki D. , Badura M. , Dawidowski W. , Tłaczała M. , Latkowska M.

Elektronika : konstrukcje, technologie, zastosowania

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2013

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tom Vol. 54, nr 10

32-35

PL

Stopy półprzewodnikowe AIIIBV z małą zawartością azotu, zwane „rozrzedzonymi azotkami”, są intensywnie badane ze względu na swoje unikalne właściwości i potencjalne zastosowanie w laserach IR i wydajnych wielozłączowych ogniwach słonecznych. Epitaksja (MOVPE lub MBE) tych materiałów jest trudna, proces kontrolowany jest głównie przez temperaturę wzrostu i koncentrację azotu w fazie gazowej. Precyzyjne wyznaczenie składu stopu InGaAsN jest złożone i wymaga zastosowania wielu technik pomiarowych. W pracy opisano technologię i optyczne właściwości niedomieszkowanych studni kwantowych 3×InGaAsN/GaAs otrzymanych metodą epitaksji z fazy gazowej z zastosowaniem związków metaloorganicznych przy ciśnieniu atmosferycznym (AP MOVPE). Testowe struktury epitaksjalne, otrzymane w różnych warunkach, zastosowano jako obszar aktywny fotodetektorów MSM. Omówiono i przeanalizowano wpływ parametrów osadzania na optyczne właściwości struktur MQW oraz ciemne i oświetlone charakterystyki dc I-V fotodetektorów MSM.

EN

AIIIBV semiconductor alloys with small amount of nitrogen, so called dilute nitrides have been extensively studied due to their unusual properties which make them very attractive for IR lasers and very efficient multijunction solar cells. The epitaxial process (MOVPE or MBE) of these materials is very difficult and strongly depends on the growth temperature and the nitrogen concentration inside an epitaxial reactor Additionally, a precise determination of the quaternary InGaAsN alloys composition is complicated and requires applying a lot of examination methods. This work presents the technology and optical properties of undoped triple quantum wells 3×InGaAsN/GaAs grown by atmospheric pressure metal organic vapour phase epitaxy (AP MOVPE). Epitaxial test structures obtained at different process conditions are used as the active regions of metal-semiconductor-metal (MSM) photodetectors. The influence of the growth parameters on the optical properties of MQW structures and measured dark and illuminated dc I-V characteristics of MSM detectors is analysed and discussed.