Wyniki wyszukiwania - BazTech

1

Fotokatalizatory i fotoelektrokatalizatory w procesach wytwarzania nadtlenku wodoru

Gańczarczyk Roman M.

Wiadomości Chemiczne

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2023

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[Z] 77, 11-12

1017--1040

EN

A significant contemporary challenge in the field of science and technology pertains to the development of innovative and sustainable methods for energy acquisition. The dynamic advancement of solar energy conversion techniques has led to the swift commercialization of photovoltaic cell technology, concomitantly creating a demand for cost-effective energy conversion and storage systems. An interesting solution to this challenge lies in the application of photocatalytic and photoelectrocatalytic synthesis to produce energy-rich molecules. One of the possible solutions under consideration in this context is hydrogen peroxide artificial photosynthesis. In recent years, several research efforts have been dedicated to the photo-assisted generation of hydrogen peroxide through oxygen reduction and water oxidation. In this brief review, the fundamental aspects related to photocatalytic and photoelectrocatalytic processes have been presented. Particular attention was paid to issues related to various groups of active photo(electro)catalysts used in the synthesis of hydrogen peroxide, and the latest trends in the molecular engineering of these compounds were highlighted.

2

Functional model for the synthesis of nanostructures of the given quality level

Suchikova Y. O., Kovachov S. S., Shishkin G. O., Pimenov D. O., Lazarenko A. S., Bondarenko V. V., Bogdanov I. T.

Archives of Materials Science and Engineering

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2021

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Vol. 107, nr 2

72--84

EN

Purpose: The aim of this paper is to develop a functional model for the synthesis of nanostructures of the given quality level, which will allow to effectively control the process of nanopatterning on the surface of semiconductors with tunable properties. Design/methodology/approach: The paper uses the IDEF0 methodology, which focuses on the functional design of the system under study and describes all the necessary processes with an accuracy sufficient for an unambiguous modelling of the system's activity. Based on this methodology, we have developed a functional model for the synthesis of nanostructures of the given quality level and tested its effectiveness through practice. Findings: The paper introduces a functional model for the synthesis of nanostructures on the surface of the given quality level semiconductors and identifies the main factors affecting the quality of nanostructures as well as the mechanisms for controlling the formation of porous layers with tunable properties. Using the example of etching single-crystal indium phosphide electrochemically in a hydrochloric acid solution, we demonstrate that the application of the suggested model provides a means of forming nanostructures with tunable properties, assessing the quality level of the nanostructures obtained and bringing the parameters in line with the reference indicators at a qualitatively new level. Research limitations/implications: Functional modelling using the IDEF0 methodology is widely used when process control is required. In this study it has been applied to control the synthesis of nanostructures of the given quality level on the surface of semiconductors. However, these studies require continuation, namely, the establishment of correlations between the technological and resource factors of synthesis and the acquired properties of nanostructures. Practical implications: This study has a significant practical effect. Firstly, it shows that functional modelling can reduce the time required to form large batches of the given quality level nanostructures. This has made it possible to substantiate the choice of the initial semiconductor parameters and nanostructure synthesis modes in industrial production from the theoretical and empirical perspective. Secondly, the presented methodology can be applied to control the synthesis of other nanostructures with desired properties and to reduce the expenses required when resources are depleted and the cost of raw materials is high. Originality/value: This paper is the first to apply the IDEF0 methodology to control the given quality nanostructure synthesis. This paper will be of value to engineers who are engaged in the synthesis of nanostructures, to researchers and scientists as well as to students studying nanotechnology.

3

Chemical evaluation of the quality of nanostructures synthesized on the surface of indium phosphide

Kovachov S. S., Bogdanov I. T., Pimenov D. O., Bondarenko V. V., Konovalenko A. A., Skurska M. M., Konovalenko I. S., Suchikova Y. O.

Archives of Materials Science and Engineering

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2021

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Vol. 110, nr 1

18--26

EN

Purpose: The article proposes a methodology for determining the chemical quality criterion of porous layers synthesized on the surface of semiconductors, based on taking into account the chemical parameters of the surface that can affect the properties of nanostructures. Design/methodology/approach: The chemical quality criterion was evaluated in terms of stoichiometry, stability of structures over time, uniformity of distribution over the surface, and the presence of an oxide phase. As an example, a calculation is demonstrated for the por-InP/InP structure synthesized on a mono-InP surface. The results of calculating the chemical quality criterion were evaluated using the Harrington scale to rank samples by quality level. Findings: A chemical criterion for the quality of porous layers synthesized on the surface of semiconductors has been developed. This criterion contains a set of indicators sufficient for a comprehensive assessment of the surface condition and is universal in nature. The studies carried out make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors and open up new perspectives in the construction of a model of self-organization of a porous structure. Research limitations/implications: The chemical quality criterion does not allow evaluating the obtained nanostructures in terms of geometric parameters. Therefore, in the future, there is a need to develop a morphological quality criterion and determine a methodology for assessing a generalized quality criterion for nanostructures synthesized on the surface of semiconductors, which may include economic, environmental, technological indicators, and the like. Practical implications: Study results are expedient from a practical point of view, since they make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors, synthesize nanostructures with predetermined properties, and create standard samples of nanomaterial composition. Originality/value: Methodology for assessing the quality of porous semiconductors by a chemical criterion has been applied for the first time in engineering science. The article will be useful to engineers, who are engaged in the synthesis of nanostructures, researchers and scientists, as well as specialists in nanometrology.

4

Effect of crystal defects on the electronic structure and dielectric functions of In0.5Tl0.5I solid state solutions

Andriyevsky Bohdan, Kashuba A., Ilchuk H.

Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej

|

2019

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Nr 15

35--56

EN

We investigate an influence of the various crystal structure imperfections on the electronic properties and dielectric functions for In0.5Tl0.5I semiconductor in the frame of the density functional theory calculations. The tensor of electron effective mass m*ij of InI, In0.5Tl0.5I and TlI crystals has been calculated for the valence and conduction bands and different K-points of Brillouin zone. Dielectric functions ε(hν) of the defective crystals based on In0.5Tl0.5I solid state solution with iodine vacancy and thallium interstitial atom were calculated taking into consideration the inter-band and intra-band electron transitions. The studies of the defective crystals reveal increased low-frequency and stationary electron conductivity with anisotropy resulted from the anisotropy of the electron effective mass tensor. Our findings explain the origin of crucial changes in the band structure by formation the donor half-occupied levels close to the unoccupied conduction bands due to the crystal structure defects, i.e. iodine vacancy or thallium interstitial atom. It has been shown that in the case of real crystals, in particular metal-halides, the proper consideration of defects in quantum-chemical calculations results in a better matching of the theoretical and experimental results in comparison to the case when the perfect crystal structure had been used for calculations.

PL

Zbadano wpływ różnych niedoskonałości struktury krystalicznej na właściwości elektronowe i funkcje dielektryczne półprzewodnika In0.5Tl0.5I w ramach teorii funkcjonału gęstości. Został obliczony tensor efektywnej masy elektronów m* kryształów InI, In0.5Tl0.5I i TlI dla pasm walencyjnych i przewodnictwa oraz różnych K-punktów strefy Brillouina. Funkcje dielektryczne ε(hν) domieszkowanych kryształów roztworów stałych In0.5Tl0.5I z wakansami jodu i atomami międzywęzłowymi talu zostały obliczone z uwzględnieniem międzypasmowych i wewnątrz-pasmowych przejść elektronowych. Badania domieszkowanych kryształów ujawniły zwiększoną przewodność elektronową niskoczęstotliwościową i stacjonarną o anizotropii wynikającej z anizotropii tensora efektywnej masy elektronów. Przeprowadzone badania wyjaśniają obserwowane duże zmiany struktury pasmowej pochodzące z utworzenia pół wypełnionych poziomów donorowych w pobliżu niezajętych pasm przewodnictwa wynikających z defektów struktury krystalicznej, tj. wakansów jodu czy atomów międzywęzłową talu. Wykazano, że w przypadku kryształów rzeczywistych, w szczególności halogenków metali, właściwe uwzględnienie defektów w obliczeniach kwantowo-chemicznych daje możliwość lepszego dopasowania obliczeń teoretycznych do wyników doświadczalnych w porównaniu do obliczeń bazujących na strukturze krystalicznej doskonałej.

5

Synthesis and characterization of high-efficiency low-cost solar cell thin film

Immanuel W. Christopher, Deborrah S. Paul Mary, Inbanathan S. S. R., Sree D. Nithyaa

Materials Science Poland

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2019

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Vol. 37, No. 1

127--135

EN

Polycrystalline chalcogenide semiconductors play a vital role in solar cell applications due to their outstanding electrical and optical properties. Among the chalcogenide semi-conductors, CdZnS is one kind of such important material for applications in various modern solid state devices such as solar cells, light emitting diode, detector etc. Due to their applications in numerous electro-optic devices, group II-VI semiconductors have been studied extensively. In recent years, major attention has been given to the study of electrical and optical properties of CdZnS thin films. In this work, Cd1−xZnxS thin films were prepared by chemical bath deposition technique. Phase purity and surface morphology properties were analyzed using field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD) studies. Chemical composition was studied using energy dispersive spectrophotometry (EDS). Optical band gap property was investigated using UV-Spectroscopy. Electrical conductivity studies were performed by two probe method and thermoelectric power setup (TEP) to determine the type of the material. This work reports the effect of Zn on structural, electrical, microstructural and optical properties of these films.

6

DFT study of optoelectronic spectra of barium cadmium chalcogenides (Ba2CdX3, X = S, Se and Te)

Kumar Sachin, Kumar Naven, Yadav Kamna, Annveer, Singh R. P.

Materials Science Poland

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2019

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Vol. 37, No. 3

417--425

EN

DFT analyses of electronic and optical spectra of barium cadmium chalcogenides (Ba2CdX3, X = S, Se, Te) have been carried out. The study of electronic spectra has been made in terms of band structure and density of states using full potential linear augmented plane wave plus local orbital method. Band structure calculations have been carried out under the approximations PBE-GGA, PBE-Sol, LDA and TB-mBJ. Band structures of these materials show that Ba2CdS3, Ba2CdSe3 and Ba2CdTe3 crystals possess a band gap less than 1 eV, underestimated relative to the experimental/theoretical literature values. Optical spectra of these chalcogenides have been analyzed in terms of real and imaginary parts of dielectric function, reflectivity, refractive index, extinction coefficient, absorption coefficient, optical conductivity and electron energy loss. Optical results show large anisotropy along different directions. These results provide a physical basis of barium cadmium chalcogenides for potential application in optoelectronic devices.

7

Local temperature rise during the electron beam characterization Calculation model for the AlxGa1-xN at low dimensions

Leghrib L, Nouiri A.

Materials Science Poland

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2018

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Vol. 36, No. 1

51--55

EN

During the characterization by electron beam techniques including scanning electron microscope (SEM) and cathodoluminescence at low dimensions, some undesirable phenomena (unwanted effects) can be created, like the thermal effects (or electron beam damage), and these effects can damage the sample. This limits the information one can get from a sample or reduces image spatial resolution. In order to understand these effects, significant efforts have been made but these studies focused on the thermal properties, without a detailed study of the causes of nanoscale heating in the bulk of samples during the SEM-characterization. Additionally, it is very difficult to measure experimentally the heating because there are many variables that can affect the results, such as the current beam, accelerating energy, thermal conductivity and size of samples. Taking into account all the factors and in order to determine the local temperature rise during the electron beam characterization of AlGaN at low dimensions, we have used a hybrid model based on combined molecular dynamics and Monte Carlo calculation of inelastic interaction of electrons with matter to calculate the temperature elevation during the SEM-characterization which can be taken into account during the characterization of AlGaN at low dimension by electron beam techniques.

8

Ag₈SnSe₆ argyrodite synthesis and optical properties

Semkiv I., Ilchuk H., Pawlowski B., Kusnezh V.

Opto-Electronics Review

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2017

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Vol. 25, No. 1

37--40

EN

The Ag₈SnSe₆ argyrodite compound was synthesized by the direct melting of the elementary Ag, Sn and Se high purity grade stoichiometric mixture in a sealed silica ampoule. The prepared polycrystalline material was characterized by the X-ray diffraction (XRD), visible (VIS) and near-infrared (NIR) reflection and photoluminescence (PL) spectroscopy. XRD showed that the Ag₈SnSe₆ crystallizes in orthorhombic structure, Pmn2₁ space group with lattice parameters: ɑ = 7.89052(6) Ǻ, b = 7.78976(6) Ǻ, c = 11.02717(8) Ǻ. Photo-luminescence spectra of the Ag₈SnSe₆ polycrystalline wafer show two bands at 1675 nm and 1460 nm. Absorption edge position estimated from optical reflectance spectra is located in the 14131540 nm wavelength range.

9

Morphologies of nanostructured bismuth sulphide and Mn (II) doped bismuth sulphide nanoparticles: characterization and application

Anasane N., Ameta R.

Materials Science Poland

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2017

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Vol. 35, No. 1

6--13

EN

Different morphologies of bismuth sulphide (Bi2S3) nanoparticles (NPs) were synthesized at room temperature using wet chemical method. The properties of bismuth sulphide (Bi2S3) nanoparticles can be controlled by different amounts of Mn2+ dopant. The synthesized nanoparticles were characterized by several techniques, such as high resolution scanning electron microscopy (HR-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), and energy dispersive X-ray spectroscopy (EDS). The nanoparticles (Bi2S3) were found to have excellent activity for the UV light assisted decolorization of methyl violet dye and also helped to speed up the redox reaction of Fe(CN)3−6 and S2O2−3. The reactions were monitored through UV-Vis spectroscopy.

10

Effect of rotation on a semiconducting medium with two-temperatures under L-S theory

Othman M. I. A., Tantawi R. S., Eraki E. E. M.

Archives of Thermodynamics

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2017

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Vol. 38, no. 2

101--122

EN

The model of the equations of generalized thermoelasticity in a semi-conducting medium with two-temperature is established. The entire elastic medium is rotated with a uniform angular velocity. The formulation is applied under Lord-Schulman theory with one relaxation time. The normal mode analysis is used to obtain the expressions for the considered variables. Also some particular cases are discussed in the context of the problem. Numerical results for the considered variables are obtained and illustrated graphically. Comparisons are also made with the results predicted in the absence and presence of rotation as well as two-temperature parameter.

11

Photosensitization of TiO2 P25 with CdS Nanoparticles for Photocatalytic Applications

Trenczek-Zając A., Banaś J., Świerczek K., Zazakowny K., Radecka M.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

841--849

EN

A TiO2/CdS coupled system was prepared by mixing the TiO2 P25 with CdS synthesized by means of the precipitation method. It was found that the specific surface area (SSA) of both components is extremely different and equals 49.5 for TiO2 and 145.4 m2·g-1 for CdS. The comparison of particle size distribution and images obtained by means of transmission electron microscopy (TEM) showed agglomeration of nanocomposites. X-ray diffraction (XRD) patterns suggest that CdS crystallizes in a mixture of cubic and hexagonal phases. Optical reflectance spectra revealed a gradual shift of the fundamental absorption edge towards longer wavelengths with increasing CdS molar fraction, which indicates an extension of the absorption spectrum of TiO2. The photocatalytic activity in UV and UV-vis was tested with the use of methyl orange (MO). The Langmuir–Hinshelwood model described well the photodegradation process of MO. The results showed that the photocatalytic behaviour of the TiO2/CdS mixture is significantly better than that of pure nanopowders.

12

Determination of CdSxSe1-x thick films optical properties from reflection spectra

Tivanov M., Kaputskaya I., Patryn A., Saad A., Survilo L., Ostretsov E.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 9

88--90

EN

A method for determining the band gap value and the refractive index near the absorption edge from reflection spectra was tested for CdSxSe1-x films prepared using the screen-printing and sintering technique.

PL

Przeanalizowano metodę wyznaczenia szerokości przerwy energetycznej i współczynnika załamania z pomiarów widma współczynnika odbicie warstw CdSxSe1-x otrzymanych metodami sitodruku i konsolidacji termicznej (sintering technique).

13

Kompleksowa charakteryzacja nowoczesnych struktur nanoelektronicznych przy użyciu Uniwersalnego Systemu Pomiarów Fotoelektrycznych

Piskorski K., Niemiec M., Borowicz L., Przewłocki H. M.

Elektronika : konstrukcje, technologie, zastosowania

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2016

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Vol. 57, nr 8

59--63

PL

Działanie przyrządów półprzewodnikowych w większości przypadków oparte jest na zjawiskach występujących w wielowarstwowych układach różnych materiałów i zależy od właściwości tych materiałów. Podstawowym elementem wchodzącym w skład niemalże każdego przyrządu półprzewodnikowego jest struktura MOS (ang. metal-oxidesemiconductor), w związku z czym struktura ta jest doskonałym narzędziem do oceny właściwości materiałowych i parametrów elektrycznych tych przyrządów. Wraz ze zmianą technologii wytwarzania struktur MOS konieczna jest umiejętność zrozumienia nowych zjawisk fizycznych w nich występujących oraz wymagany jest dalszy rozwój metod badawczych. Wiele kluczowych parametrów badanych struktur może być bardzo dokładnie wyznaczona na podstawie pomiarów fotoelektrycznych co sprawia, że metody te zyskują duże znaczenie w charakteryzacji rozmaitych struktur nanoelektronicznych. W pracy przedstawiono wyniki pomiarów elektrycznych i fotoelektrycznych wykonanych na wielu strukturach MOS w celu prezentacji możliwości uniwersalnego Systemu Pomiarów Fotoelektrycznych. System ten powstał w Zakładzie Charakteryzacji Struktur Nanoelektronicznych ITE na podstawie własnych koncepcji i założeń i realizuje oryginalne metody pomiarowe opracowane w tym Zakładzie.

EN

In this work the universal System for Photoelectric Measurements (USPM) is presented. This system, designed and constructed in Department of Characterisation of Nanoelectronic Structures (Institute of Electron Technology, Warsaw) allows measurements of several important parameters of the investigated MOS structures. Some of the key parameters (e.g. effective contact potential difference, barrier heights on both sides of the dielectric layer) can be measured using photoelectric techniques which are known as the most accurate measurement methods of these parameters. The USPM system realizes measurements of different types of MOS structure characteristics, such as photocurrent-voltage IF(VG), capacitances-voltage C(VG) and other, examples of these measurements are shown in the article.

14

Comparative molecular dynamics studies of Si, GaN and SiC thermal conductivity

Andriyevsky B.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 9

5-8

EN

Thermal conductivity of Si, SiC and GaN crystals have been calculated by the reversed non-equilibrium molecular dynamics method using the Forcite program with the Universal force field potentials of the Materials Studio 7.0 package. The dependencies of thermal conductivity on the length of crystal’s supercell and density have been obtained and analyzed. Correlation of the degree of hybridization of vibrations of Si and C in SiC and Ga and N in GaN, from the one side, and coefficient of thermal conductivity, from the other one, has been revealed.

PL

Obliczono przewodność cieplną kryształów Si, SiC i GaN metodą odwrotnej nierównoważnej dynamiki molekularnej za pomocą programu Forcite przy potencjałach pól siłowych typu Universal z pakietu Materials Studio 7.0. Otrzymano i przeanalizowano zależności przewodności cieplnej kryształów w funkcji długości odpowiedniej superkomórki oraz gęstości. Ujawniono korelację stopnia hybrydyzacji drgań atomów Si i C w SiC oraz Ga i N w GaN, z jednej strony, a współczynnika przewodności cieplnej, z drugiej.

15

Praktyczne aspekty wytrzymałości zwarciowej urządzeń z półprzewodnikami mocy

Przybysz J., Owsiński M., Piątek Z.

Prace Instytutu Elektrotechniki

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2015

|

Z. 270

47--61

PL

W ramach prowadzonych w Instytucie Energetyki w Warszawie badań urządzeń elektroenergetycznych wykonywane są między innymi próby sprawdzania ich wytrzymałości zwarciowej. W niniejszym artykule zebrano doświadczenia uzyskane podczas badań dla elementów półprzewodnikowych dużej mocy. Przedstawiono zachowanie się obiektów wyposażonych w elementy półprzewodnikowe, między innymi podczas łączenia prądów zwarciowych w stanie pracy znamionowej i awaryjnej. Pokazano zalety stosowania takich rozwiązań oraz omówiono zasadność wykonywania badań pozwalających uzyskać charakterystyki dynamiczne wykorzystywanych elementów półprzewodnikowych. Zwrócono również uwagę na zalety wykorzystania na etapie konstruktorskim zależności przejściowej impedancji termicznej struktur półprzewodników.

EN

Short-circuit withstand of electric power system equipment is a part of the tests carried out by Institute of Power Engineering in Warsaw. In this article we have gathered our experience gained during the research of the power semiconductor devices. It shows the behavior of devices equipped with semiconductor components during short-circuit currents flow in case of nominal and emergency operation. The advantages of such solutions and method of obtaining the dynamic characteristics of semiconductor devices were shown as well. Attention was also drawn to the advantages of the use of transient thermal impedance based on semiconductor structures during the designing stage.

16

Electronic parameters of MIS Schottky diodes with DNA biopolymer interlayer

Gullu O., Turut A.

Materials Science Poland

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2015

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Vol. 33, No. 3

593--600

EN

In this work, we prepared an ideal Cu/DNA/n-InP biopolymer-inorganic Schottky sandwich device formed by coating a n-InP semiconductor wafer with a biopolymer DNA. The Cu/DNA/n-InP contact showed a good rectifying behavior. The ideality factor value of 1.08 and the barrier height (Φb) value of 0.70 eV for the Cu/DNA/n-InP device were determined from the forward bias I-V characteristics. It was seen that the Φb value of 0.70 eV obtained for the Cu/DNA/n-InP contact was significantly larger than the value of 0.48 eV of conventional Cu/n-InP Schottky diodes. Modification of the interfacial potential barrier of Cu/n-InP diode was achieved using a thin interlayer of DNA biopolymer. This was attributed to the fact that DNA biopolymer interlayer increased the effective barrier height by influencing the space charge region of InP.

17

Niebieskie, zielone i białe emitery światła wytwarzane z półprzewodników AIII-BN

Rudziński M., Wesołowski M., Strupiński W.

Przegląd Elektrotechniczny

|

2014

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R. 90, nr 7

1--13

PL

Postępy w ostatnich dwudziestu pięciu latach w epitaksji i technologii wytwarzania materiałów z grupy AIII-BN doprowadziły do wytworzenia komercyjnych, wysoko wydajnych źródeł światła emitujących w kolorach ultrafioletu, niebieskim, zielonym i białym. W pracy przedstawiono przegląd technologii wytwarzania diod elektroluminescencyjnych z materiałów AIII-BN, między innymi różne rozwiązania strukturalne, uwzględniające właściwości materiałowe i wymagania wzrostu krystalicznego MOCVD. Przeanalizowano różne konstrukcje ekstrakcji światła, które są istotne dla uzyskania jak najwyższej wydajności zewnętrznego świecenia. Zaprezentowano najnowsze osiągnięcia dotyczące zewnętrznej wydajności kwantowej dla wysokiej mocy diod elektroluminescencyjnych, jak również wydajności świecenia białych diod opartych na konwersji światła przy użyciu luminoforów.

EN

Recent twenty five years of advances in epitaxial growth and fabrication technologies for the III-Nitrides have led to commercially available, high efficient solid state devices that emits ultraviolet, blue, green and white light. In this work LEDs technologies based on III-Nitrides have been presented. Different structural design choices are described, taking into account specific material properties and MOCVD crystal growth requirement. We review various light extraction schemes which are important for achieving the highest possible light output efficiencies. Recent performance in external quantum efficiency for high power LEDs is reviewed, as well as luminous efficacy of white LEDs based on luminophores down-conversion.

18

Investigations of the Implanted Layer in Silicon Based on the Modulated Free Carrier Absorption Phenomenon

Maliński M. A., Chrobak Ł. B., Bychto L., Pawlak M.

Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej

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2013

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Nr 5

17--22

EN

This paper presents experimental amplitude MFCA characteristics of the implanted silicon samples. Influence of the silicon implantation process for frequency MFCA characteristics has been analyzed. The idea and the experimental set-up of the proposed method have been presented and discussed. This paper proves that is possible to estimate depth of the implanted layer from MFCA experimental data.

PL

W artykule przedstawiono eksperymentalne charakterystyki MFCA dla próbek implantowanego krzemu. Przeanalizowano wpływ procesu implantacji krzemu na charakterystyki MFCA. Przedstawiono i poddano dyskusji ideę zaproponowanej metody oraz stanowisko eksperymentalne. Praca udowadnia, że możliwa jest estymacja głębokości warstwy implantowanej na podstawie eksperymentalnych charakterystyk MFCA.

19

Transmisja i przetwarzanie sygnałów optycznych o wysokich przepływnościach wykorzystująca półprzewodnikowe wzmacniacze optyczne

Turkiewicz J. P.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2013

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z. 192

3--142

PL

W niniejszej pracy przedstawiono badania nad możliwością poszerzenia wykorzystania półprzewodnikowych wzmacniaczy optycznych SOA w systemach optotelekomunikacyjnych. Badania objęły zastosowania wzmacniaczy SOA zarówno do transmisji sygnałów, jak i całkowicie optycznego przetwarzania sygnałów. W ramach pracy naukowo-badawczej przebadano możliwość realizacji systemów DWDM o uproszczonej budowie i dużej pojemności transmisyjnej, wykorzystujących wzmacniacze SOA. Przebadano najważniejsze ograniczenia transmisji w oknie telekomunikacyjnym 1310 nm i określono zależności między pojemnością a zasięgiem dla badanej klasy systemów transmisyjnych. Zrealizowano i przebadano eksperymentalny system transmisyjny DWDM 8x40 Gbit/s i 8x54 Gbit/s wykorzystując SOA na pasmo 1310 nm. Przedstawiony system transmisyjny może być wykorzystany zarówno do połączeń 400 G i 1000 G Ethernet, jak i dla potrzeb centrów gromadzenia oraz przetwarzania informacji. W dalszej części pracy zaproponowano i przebadano innowacyjną metodę konwencji formatu modulacji OOK-QAM. Przedstawiono zasadę działania konwertera formatu modulacji OOK-QAM. Przedstawiono zasadę działania konwertera formatu modulacji OOK-QAM wykorzystującego konwertery długości fali. Następnie zweryfikowano możliwość generacji sygnałów 16-QAM w konwerterze wykorzystującym dwie równolegle połączone struktury SOA-MZI. Określono wrażliwość generowania sygnałów 160 Gbit/s 16-QAM na typowe zniekształcenia w transmisji światłowodowej oraz możliwość ich wykorzystania w systemach transmisyjnych o bardzo wysokiej pojemności. Przeprowadzone badania potwierdziły poprawną generację sygnału 16-QAM w proponowanym układzie konwertera formatu modulacji. Zaproponowany konwerter formatu modulacji może być wykorzystany do realizacji całkowicie optycznego styku sieci OOK i QAM oraz do generacji sygnałów o bardzo wysokich przepływnościach.

EN

The present work is dedicated to research on further expansion of semiconductor optical amplifier SOA applications in opto-telecommunication systems. The research covers transmission and all-optical signal processing applications. The feasibility to realize low-complexity high capacity DWDM transmission utilizing semiconductor optical amplifiers in the 1310 nm window is verified. Major transmission limitation in the 1310 nm window are identified, along with a presentation of countermeasures. The trade of between transmission capacity and distance is investigated. The 8x40 Gbit/s and 8x54 Gbit/s DWDM transmission system in the 1310 nm window utilizing semiconductor optical amplifiers was built and tested. The demonstrated system can be utilized in ultra-high speed 400 G and 1000 G Ethernet, as well as inter and intra center transmission. Next, a novel all-optical OOK-QAM modulation format conversion method has been presented. The principle of operation of the OOK-QAM modulation format converter based on the wavelength conversion is explained. Further feasibility of the 16-QAM signal generation in the proposed modulation format converter utilizing two parallel SOA-MZI is investigated including studies on the generated 160Gbit/s 16-QAM signal resilience to the typical fibre transmission impairments. The conducted wok has shown proper operation of the investigated OOK-QAM modulation format converter. The proposed converter can be applied at the OOK and QAM networks interface and to generate ultra-high bit rate signals.

20

Energy efficiency of near infrared cobalt luminscence in ZnSe:Co determined by a photoacoustic method

Chrobak Ł., Maliński M., Strzałkowski K., Zakrzewski Z.

Opto-Electronics Review

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2012

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Vol. 20, No. 1

91-95

EN

The paper presents results of computations of the energy efficiency of the cobalt luminescence in ZnSe:Co determined by the photoacoustic method. The transmission spectra, photoacoustic experimental and theoretical spectra, and the frequency dependence on the photoacoustic amplitude characteristics are presented. From them, the energy efficiency of Co²⁺ the near infrared luminescence (3200 nm) was computed in the frame of new proposed photoacoustic model of computations of the luminescence energy efficiency.