48 results on '"G. Zatryb"'
Search Results
2. Effect of Air Exposure of ZnMgO Nanoparticle Electron Transport Layer on Efficiency of Quantum-Dot Light-Emitting Diodes
- Author
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Artur Podhorodecki, Maciej Chrzanowski, G. Zatryb, and P. Sitarek
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Photoluminescence ,Materials science ,air exposure ,device stability ,light-emitting diodes ,Quantum yield ,quantum dots ,charge balance ,02 engineering and technology ,Electron ,010402 general chemistry ,01 natural sciences ,law.invention ,law ,General Materials Science ,Leakage (electronics) ,Diode ,business.industry ,ZnMgO nanoparticles ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Quantum dot ,Optoelectronics ,Quantum efficiency ,0210 nano-technology ,business ,Research Article ,Light-emitting diode - Abstract
We demonstrate the effect of air exposure on optical and electrical properties of ZnMgO nanoparticles (NPs) typically exploited as an electron transport layer in Cd-based quantum-dot light-emitting diodes (QLEDs). We analyze the roles of air components in modifying the electrical properties of ZnMgO NPs, which reveals that H2O enables the reduction of hole leakage while O2 alters the character of charge transport due to its ability to trap electrons. As a result, the charge balance in the QDs layer is improved, which is confirmed by voltage-dependent measurements of photoluminescence quantum yield. The maximum external quantum efficiency is improved over 2-fold and reaches the value of 9.5% at a luminance of 104 cd/m2. In addition, we investigate the problem of electron leakage into the hole transport layer and show that trap-mediated electron transport in the ZnMgO layer caused by adsorbed O2 ensures a higher leakage threshold. This work also provides an insight into the possible disadvantages of device contact with air as well as problems and challenges that might occur during open-air fabrication of QLEDs.
- Published
- 2021
3. Enhanced photoluminescence stability of CdS nanocrystals through a zinc acetate reagent
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Jan Misiewicz, G. Zatryb, Mateusz Banski, Maciej Chrzanowski, and Artur Podhorodecki
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Materials science ,Photoluminescence ,General Chemical Engineering ,Kinetics ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Zinc ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Photobleaching ,0104 chemical sciences ,Nanocrystal ,chemistry ,Reagent ,Photodarkening ,0210 nano-technology ,Luminescence - Abstract
In this study, the role of a zinc acetate precursor in improving the luminescence stability of purple-emitting CdS nanocrystals is investigated. The oleate-capped core of CdS nanocrystals exhibits intense photodarkening under prolonged UV excitation. From the results of photoluminescence experiments, we can observe that photobleaching is responsible for the degradation of temporal stability, i.e., decline in photoluminescence intensity. Herein, we demonstrate that by adding zinc acetate to the synthesis solution, one can enhance the photoluminescence stability by the complete suppression of the bleaching processes of nanocrystals. We can distinguish between the effects caused by zinc ions and those caused by acetate ligands. Acetate ligands improve the photoluminescence stability of the core of CdS nanocrystals. However, only when zinc acetate is used, the PL stability can be conserved at high excitation power. Simultaneously, we have studied the influence of zinc cations and acetate ligands on the kinetics of nanocrystal growth. The presented results underline the importance of short surface capping ligands and zinc cations in CdS nanocrystal synthesis. This study exhibits a new advantage of exploiting zinc acetate reagents in one-pot nanocrystal synthesis.
- Published
- 2018
4. Optical Stability of Thick‐Shell CdSe@ZnS/ZnS Quantum Dots Dissolved in n ‐Octane in Wide Range of Mass Concentration: Photoluminescence Decay Study
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Anna Lesiak, Adrian Adamski, G. Zatryb, Maciej Chrzanowski, and Artur Podhorodecki
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Range (particle radiation) ,Photoluminescence ,Materials science ,Quantum dot ,Shell (structure) ,Analytical chemistry ,Mass concentration (chemistry) ,Colloidal quantum dots ,Condensed Matter Physics ,Optical stability ,N octane ,Electronic, Optical and Magnetic Materials - Published
- 2021
5. Influence of europium on structure modification of TiO2 thin films prepared by high energy magnetron sputtering process
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Des Gibson, G. Zatryb, Jan Misiewicz, Damian Wojcieszak, Danuta Kaczmarek, and Michal Mazur
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010302 applied physics ,Anatase ,Materials science ,Dopant ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Sputter deposition ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Nanocrystalline material ,Surfaces, Coatings and Films ,symbols.namesake ,chemistry ,0103 physical sciences ,Materials Chemistry ,symbols ,Thin film ,0210 nano-technology ,Europium ,Raman spectroscopy - Abstract
In this work modification of TiO2 thin films structure by doping with europium was described. Nanocrystalline films were prepared by high energy magnetron sputtering process. The influence of europium on the microstructure of TiO2 was determined based on the results of X-ray diffraction, transmission electron microscopy, Raman spectroscopy and photoluminescence measurements. It was found that undoped film had rutile structure directly after deposition (without additional annealing), while 0.2 at.% and 0.4 at.% of the dopant was sufficient to receive TiO2 films with anatase form. The type of structure was confirmed with the aid of Raman spectroscopy and by TEM observations. The amount of Eu-dopant had direct impact on PL intensity as well as presence of defect (voids) in the film.
- Published
- 2017
6. Influence of rapid thermal annealing temperature on the photoluminescence of Tb ions embedded in silicon nitride films
- Author
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Christophe Labbé, P. Benzo, Julien Cardin, Jan Misiewicz, Artur Podhorodecki, Fabrice Gourbilleau, L W Golacki, G. Zatryb, M.M. Klak, Institute of Physics [Wroclaw], Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physiologie et Génomique des Poissons (LPGP), Institut National de la Recherche Agronomique (INRA)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), and Cardin, Julien
- Subjects
[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics] ,Photoluminescence ,Materials science ,[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic ,Annealing (metallurgy) ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph] ,Analytical chemistry ,chemistry.chemical_element ,Terbium ,02 engineering and technology ,[SPI.MAT] Engineering Sciences [physics]/Materials ,01 natural sciences ,Ion ,[SPI.MAT]Engineering Sciences [physics]/Materials ,[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph] ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,0103 physical sciences ,Materials Chemistry ,Photoluminescence excitation ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,010302 applied physics ,[CHIM.MATE] Chemical Sciences/Material chemistry ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,[SPI.ELEC] Engineering Sciences [physics]/Electromagnetism ,Metals and Alloys ,Surfaces and Interfaces ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,[PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[SPI.ELEC]Engineering Sciences [physics]/Electromagnetism ,Silicon nitride ,chemistry ,Excited state ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,0210 nano-technology ,Excitation - Abstract
International audience; In this work, silicon nitride films containing terbium were deposited by reactive magnetron co-sputtering in a nitrogen enriched plasma and subjected to rapid thermal annealing treatments. The influence of annealing temperature on the emission and absorption properties of these films was investigated by photoluminescence, photoluminescence decay and photoluminescence excitation measurements. An increase in the photo-luminescence intensity and photoluminescence decay time was observed upon annealing for the main 5 D 4-7 F 5 transition of Tb 3+ ions. This observation was attributed to decrease of the non-radiative recombination and increase of the number of excited Tb 3+ ions upon annealing. Moreover, high temperature annealing was found to shift the spectral position of absorption bands observed in the photoluminescence excitation spectra. In general, these excitation spectra were shown to have a rather complicated structure and were decomposed into three Gaussian bands. It was suggested that two of these excitation bands might be due to indirect excitation of Tb 3+ ions via defects and the third excitation band could be due to direct 4f-5d transition.
- Published
- 2019
7. Mechanism of enhanced photoluminescence of Tb ions in hydrogenated silicon-rich silicon oxide films
- Author
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Artur Podhorodecki, M.M. Klak, Peter Mascher, G. Zatryb, Jacek Wojcik, and Jan Misiewicz
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010302 applied physics ,Materials science ,Photoluminescence ,Passivation ,Hydrogen ,Silicon ,Metals and Alloys ,Oxide ,chemistry.chemical_element ,Terbium ,02 engineering and technology ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Materials Chemistry ,0210 nano-technology ,Silicon oxide - Abstract
Terbium-doped silicon-rich silicon oxide films were deposited and hydrogenated at elevated temperatures. The influence of hydrogenation on defects-mediated non-radiative recombination of excited Tb 3+ ions was investigated by means of photoluminescence and photoluminescence decay measurements. An increase in photoluminescence intensity and photoluminescence decay time was observed upon hydrogenation for the main 5 D 4 – 7 F 5 transition of Tb 3+ ions. This observation was ascribed to saturation of non-radiative recombination defect centers with hydrogen. It was found that the number of emitted photons increases upon passivation as a result of two effects: (1) a reduction of the non-radiative recombination rate, and (2) optical activation of new Tb 3+ emitters. Based on the obtained results and literature data, Forster energy-transfer was suggested as the interaction responsible for the non-radiative coupling between Tb 3+ ions and defects.
- Published
- 2016
8. On the choice of proper average lifetime formula for an ensemble of emitters showing non-single exponential photoluminescence decay
- Author
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Michal Mateusz Klak and G. Zatryb
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Physics ,Normalization (statistics) ,Photoluminescence ,Probability density function ,02 engineering and technology ,Function (mathematics) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Decay curve ,Interpretation (model theory) ,Exponential function ,Excited state ,0103 physical sciences ,General Materials Science ,Statistical physics ,010306 general physics ,0210 nano-technology - Abstract
In this paper, we investigate non-single exponential photoluminescence decays in various disordered condensed-matter systems. For such materials, two formulas for the average lifetime of system’s excited state are commonly used in the analysis of experimental data. In many cases, the choice of formula is arbitrary and lacks a clear physical justification. For this reason, our main goal is to show that the choice of correct mathematical formula should be based on the interpretation of measured photoluminescence decay curve. It is shown that depending on the investigated system, after appropriate normalization, photoluminescence decay curve can represent either a survival probability function or a probability density function of lifetime and for this reason two different formulas for the average lifetime are required. It is also shown that, depending on luminescence quantum yield, some information on the probability density function of lifetime can be lost in the process of measurement, which results in underestimated values of average lifetime. Finally, we provide an interpretation of total decay rate distributions which are frequently obtained by phenomenological modeling of non-single exponential photoluminescence decays.
- Published
- 2020
9. Influence of Nd dopant amount on microstructure and photoluminescence of TiO2:Nd thin films
- Author
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Danuta Kaczmarek, Jerzy Morgiel, Jan Misiewicz, Michal Mazur, G. Zatryb, Damian Wojcieszak, and Jaroslaw Domaradzki
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Materials science ,Photoluminescence ,Dopant ,Band gap ,Organic Chemistry ,Analytical chemistry ,chemistry.chemical_element ,Sputter deposition ,Neodymium ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry ,Absorption edge ,Sputtering ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Thin film ,Spectroscopy - Abstract
TiO2 and TiO2:Nd thin films were deposited using reactive magnetron sputtering process from mosaic Ti–Nd targets with various Nd concentration. The thin films were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and spectroscopic techniques. Photoluminescence (PL) in the near infrared obtained upon 514.5 nm excitation was also examined. The relationship between the Nd concentration, structural, optical and photoluminescence properties of prepared thin films was investigated and discussed. XRD and TEM measurements showed that an increase in the Nd concentration in the thin films hinders the crystal growth in the deposited coatings. Depending on the Nd amount in the thin films, TiO2 with the rutile, mixed rutile–amorphous or amorphous phase was obtained. Transmittance measurements revealed that addition of Nd dopant to titania matrix did not deteriorate optical transparency of the coatings, however it influenced on the position of the fundamental absorption edge and therefore on the width of optical band gap energy. All TiO2:Nd thin films exhibited PL emission that occurred at ca. 0.91, 1.09 and 1.38 μm. Finally, results obtained for deposited coatings showed that titania with the rutile structure and 1.0 at.% of Nd was the most efficient in VIS to NIR photon conversion.
- Published
- 2015
10. Effect of the nanocrystalline structure type on the optical properties of TiO2:Nd (1at.%) thin films
- Author
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Danuta Kaczmarek, G. Zatryb, Jerzy Morgiel, Jan Misiewicz, Jaroslaw Domaradzki, Damian Wojcieszak, and Michal Mazur
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Anatase ,Materials science ,genetic structures ,Band gap ,business.industry ,Organic Chemistry ,Microstructure ,eye diseases ,Atomic and Molecular Physics, and Optics ,Nanocrystalline material ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry.chemical_compound ,Optics ,chemistry ,Rutile ,Sputtering ,Titanium dioxide ,Optoelectronics ,sense organs ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Thin film ,business ,Spectroscopy - Abstract
Titanium dioxide thin films, each doped with the same amount of neodymium (1 at.%) were deposited by Low Pressure Hot Target Reactive Sputtering and High Energy Reactive Magnetron Sputtering processes in order to obtain anatase and rutile thin film structures respectively. The microstructure and phase composition were analyzed using the transmission electron microscopy method including high resolution electron microscopy imaging. The measurements of the optical properties showed, that both prepared thin films were transparent in the visible light range and had a low extinction coefficient of ca. 3 ⋅ 10−3. The thin film with the anatase structure had a lower cut-off wavelength and refractive index and a higher value of optical energy band gap as-compared to the TiO2:Nd coating with the rutile structure. Simultaneously, more efficient photoluminescence emission was observed for the rutile thin films.
- Published
- 2015
11. Stress transition from compressive to tensile for silicon nanocrystals embedded in amorphous silica matrix
- Author
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Jan Misiewicz, Peter Mascher, P. R. J. Wilson, Jacek Wojcik, Artur Podhorodecki, and G. Zatryb
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010302 applied physics ,Materials science ,Silicon ,Metals and Alloys ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Stress (mechanics) ,chemistry ,Nanocrystal ,Absorption edge ,Quantum dot ,Plasma-enhanced chemical vapor deposition ,0103 physical sciences ,Ultimate tensile strength ,Materials Chemistry ,Composite material ,0210 nano-technology ,Silicon oxide - Abstract
Silicon-rich silicon oxide films, with various Si concentrations, were deposited by plasma enhanced chemical vapor deposition and annealed at 1100 °C in order to form silicon nanocrystals. For these films, it has been found that the absorption edge shifts as a function of the nanocrystal size due to the quantum confinement of exciton. This result showed that the size-related effects are present in the investigated films. Next, we examined the influence of the nanocrystal size on the vibrational modes. In this case, the Raman line related to silicon nanocrystals significantly down-shifts as a function of the nanocrystal size, which is against the predictions of the phonon confinement model. It has been shown that this effect is due to stress exerted on the nanocrystals. It has been also found that this stress changes from compressive to tensile, and the stress character depends on the film stoichiometry.
- Published
- 2014
12. Structural and emission properties of Tb3+-doped nitrogen-rich silicon oxynitride films
- Author
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Philippe Marie, Christophe Labbé, Fabrice Gourbilleau, Julien Cardin, Xavier Portier, Artur Podhorodecki, Yong-Tao An, Cédric Frilay, G. Zatryb, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Department of Experimental Physics, Polonium Partenariat Hubert Curien PHC (PHC N° 27720WC), ANR-13-BS09-0020,GENESE,Gestion de la lumièrE pour la future géNération de cEllules SolairEs(2013), ANR-10-LABX-0009,EMC3,Energy Materials and Clean Combustion Center(2010), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)
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Photoluminescence ,Silicon oxynitride ,Materials science ,Annealing (metallurgy) ,Analytical chemistry ,FOS: Physical sciences ,Bioengineering ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,0103 physical sciences ,General Materials Science ,Electrical and Electronic Engineering ,Thin film ,Silicon oxide ,010302 applied physics ,Condensed Matter - Materials Science ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Mechanical Engineering ,Doping ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,Amorphous solid ,chemistry ,Silicon nitride ,Mechanics of Materials ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,0210 nano-technology ,Physics - Optics ,Optics (physics.optics) - Abstract
Terbium doped silicon oxynitride host matrix is suitable for various applications such as light emitters compatible with CMOS technology or frequency converter systems for photovoltaic cells. In this study, amorphous Tb3+ ion doped nitrogen-rich silicon oxynitride (NRSON) thin films were fabricated using a reactive magnetron co-sputtering method, with various N2 flows and annealing conditions, in order to study their structural and emission properties. Rutherford backscattering (RBS) measurements and refractive index values confirmed the silicon oxynitride nature of the films. An electron microscopy analysis conducted for different annealing temperatures (T A) was also performed up to 1200 {\textdegree}C. Transmission electron microscopy (TEM) images revealed two different sublayers. The top layer showed porosities coming from a degassing of oxygen during deposition and annealing, while in the region close to the substrate, a multilayer-like structure of SiO2 and Si3N4 phases appeared, involving a spinodal decomposition. Upon a 1200 {\textdegree}C annealing treatment, a significant density of Tb clusters was detected, indicating a higher thermal threshold of rare earth (RE) clusterization in comparison to the silicon oxide matrix. With an opposite variation of the N2 flow during the deposition, the nitrogen excess parameter (Nex) estimated by RBS measurements was introduced to investigate the Fourier transform infrared (FTIR) spectrum behavior and emission properties. Different vibration modes of the Si--N and Si--O bonds have been carefully identified from the FTIR spectra characterizing such host matrices, especially the 'out-of-phase' stretching vibration mode of the Si--O bond. The highest Tb3+ photoluminescence (PL) intensity was obtained by optimizing the N incorporation and the annealing conditions. In addition, according to these conditions, the integrated PL intensity variation confirmed that the silicon nitride-based host matrix had a higher thermal threshold of rare earth clusterization than its silicon oxide counterpart. Analysis of time-resolved PL intensity versus T A showed the impact of Tb clustering on decay times, in agreement with the TEM observations. Finally, PL and PL excitation (PLE) experiments and comparison of the related spectra between undoped and Tb-doped samples were carried out to investigate the impact of the band tails on the excitation mechanism of Tb3+ ions.
- Published
- 2017
13. Structural and emission properties of Tb
- Author
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C, Labbé, Y-T, An, G, Zatryb, X, Portier, A, Podhorodecki, P, Marie, C, Frilay, J, Cardin, and F, Gourbilleau
- Abstract
Terbium doped silicon oxynitride host matrix is suitable for various applications such as light emitters compatible with CMOS technology or frequency converter systems for photovoltaic cells. In this study, amorphous Tb
- Published
- 2017
14. Optical properties of Tb and Eu doped cubic YAlO3 phosphors synthesized by sol–gel method
- Author
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N. V. Gaponenko, Jan Misiewicz, Jarosław Serafińczuk, Artur Podhorodecki, G. Zatryb, Mateusz Banski, and Marcin Motyka
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Photoluminescence ,Materials science ,Dopant ,Organic Chemistry ,Doping ,chemistry.chemical_element ,Mineralogy ,Terbium ,Phosphor ,Yttrium ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry ,Nanocrystal ,Physical chemistry ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Europium ,Spectroscopy - Abstract
In this work, terbium and europium doped YAlO3 phosphors were synthesized by sol–gel method. It has been shown that after annealing at 1000 °C these phosphors crystallize in the cubic garnet phase, similar to Y3Al5O12. As evidenced by the time-resolved photoluminescence spectroscopy and Maximum Entropy Method, the photoluminescence decay of both europium 5D0 and terbium 5D4 states has two lifetime components: short and long, both of the order of milliseconds. Moreover, for both phosphors the short photoluminescence lifetime was ascribed to the ions occupying low-symmetry sites in the vicinity of the nanocrystal surface, while the long decay component was related to the ions present in the bulk of YAlO3 nanocrystal. For both dopants, the long lifetime component of Tb3+ and Eu3+ emission is longer than the equivalent lifetimes in bulk Y3Al5O12 crystal.
- Published
- 2013
15. Influence of Pressure-Induced Transition from Nanocrystals to Nanoceramic Form on Optical Properties of Ce-Doped Y3Al5O12
- Author
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G. Zatryb, Pawel Gluchowski, Wieslaw Strek, Jan Misiewicz, Marcin Syperek, Artur Podhorodecki, and Witold Lojkowski
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Materials science ,Photoluminescence ,Nanocrystal ,Scanning electron microscope ,Doping ,Materials Chemistry ,Ceramics and Composites ,Analytical chemistry ,Spectroscopy ,Nanoceramic ,Amorphous solid ,Ion - Abstract
In this work, we have examined modifications of structural and optical properties of Y3Al5O15:Ce3+ (Ce3+:YAG) material when transforming from nanograins to nanoceramic form under high pressure. Initial YAG material with 0.5% of Ce3+ was prepared using modified Pechini and transformed to nanoceramic at low temperature with a working pressure of 4 GPa. Structural properties of both samples (nanopowder and nanoceramic) have been examined with X-ray diffraction and scanning electron microscope. Optical properties have been examined using photoluminescence (PL) spectroscopy, PL-excitation spectroscopy at different temperatures, and time-resolved spectroscopy. Based on results obtained, excitation mechanism of Ce3+ ions has been explained. The main 560 nm emission band along with a new 400 nm emission band allowed to cover the whole visible spectral range. Moreover, it has been found that under high-pressure treatment the amorphous shell of YAG core appears, leading to increased 5d electrons–lattice interaction. This, in turn, reduces PL decay time and increases emission intensity of nanoceramic sample.
- Published
- 2011
16. Utilization of GaN:Eu3+ nanocrystals for the detection of programmed cell death
- Author
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Alexander Zaichenko, A. Podhorodecki, Rostyslav Bilyy, G. Zatryb, Rostyslav Stoika, Marcin Nyk, Jan Misiewicz, and Wieslaw Strek
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Programmed cell death ,Nanoparticle ,chemistry.chemical_element ,Nanotechnology ,Gallium nitride ,Conjugated system ,Condensed Matter Physics ,Fluorescence ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Nanocrystal ,chemistry ,Microscopy ,Biophysics ,Europium - Abstract
In the current study we propose to use a new system for labeling biological processes. Gallium nitride nanocrystals doped by europium ions (nc-GaN:Eu 3+ ) have been obtained and used to identify the cells undergoing process of programmed cell death. Obtained by combustion method, GaN:Eu 3+ fluorescent nanocrystals have been covered with the polymeric envelope, bearing epoxy groups. Carbohydrate-binding protein-lectin-specifically recognizing cells undergoing programmed cell death was conjugated to the envelope of nanoparticles. Incubation of alive and dead cells with nanoparticles suspension and subsequent analysis using fluorescent and phase-contrast microscopy revealed predominate binding of nanoparticles to dead cells, while intact cell did not bind nanoparticles under the same conditions.
- Published
- 2008
17. Raman scattering from confined acoustic phonons of silicon nanocrystals in silicon oxide matrix
- Author
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Artur Podhorodecki, P. R. J. Wilson, Jan Misiewicz, G. Zatryb, Peter Mascher, and Jacek Wojcik
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Materials science ,Scattering ,Phonon ,Nucleation ,Nanocrystalline silicon ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Molecular physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Condensed Matter::Materials Science ,symbols.namesake ,Nanocrystal ,law ,Condensed Matter::Superconductivity ,0103 physical sciences ,symbols ,Crystallization ,010306 general physics ,0210 nano-technology ,Silicon oxide ,Raman scattering - Abstract
In this work, silicon-rich silicon oxide films of different stoichiometry were annealed at high temperatures in order to obtain silicon nanocrystals embedded in silica. The low-frequency Raman scattering has been observed and related to acoustic phonons confined in these nanocrystals. It has been found that this scattering consists of two modes: one at a lower frequency and one at a higher frequency. The depolarization ratios for these modes were determined, showing that the lower frequency mode is depolarized and the higher frequency mode is polarized. It has been also found that under specific conditions of film preparation the product of mode frequency and nanocrystal diameter is scale invariant. Finally, it has been shown that the confined acoustic phonon frequencies do not simply depend on the nanocrystal size alone, but also on the Si concentration in the film itself. This effect has been ascribed to the accelerated nucleation and enhanced crystallization occurring in the films deposited with higher Si content.
- Published
- 2015
18. Excitation mechanism of europium ions embedded into TiO2 nanocrystalline matrix
- Author
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Jan Misiewicz, P. Sitarek, Eugeniusz Prociow, Jaroslaw Domaradzki, A. Borkowska, Danuta Kaczmarek, Artur Podhorodecki, and G. Zatryb
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Photoluminescence ,Chemistry ,Surface photovoltage ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Surfaces and Interfaces ,Molecular physics ,Nanocrystalline material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Condensed Matter::Materials Science ,Materials Chemistry ,Photoluminescence excitation ,Europium ,Spectroscopy ,Excitation - Abstract
article i nfo In this work, the excitation mechanism of Eu 3+ ions embedded into nanocrystalline TiO2 film obtained by Low Pressure Hot Target Reactive Sputtering has been investigated by means of photoluminescence, photoluminescence excitation, transmission and surface photovoltage spectroscopy. The strong emission related to europium ions in the visible range has been observed at a non resonant excitation wavelength suggesting an efficient excitation transfer from the matrix to the ions. Based on obtained results, indirect excitation mechanism of europium ions has been confirmed and discussed. Moreover, surface activity strongly depending on environment conditions, has been also observed.
- Published
- 2009
19. On the origin of emission and thermal quenching of SRSO:Er3+ films grown by ECR-PECVD
- Author
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Peter Mascher, Jan Misiewicz, G. Zatryb, Artur Podhorodecki, L W Golacki, and Jacek Wojcik
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Silicon ,78.40.Fy ,Photoluminescence ,Materials science ,Physics::Instrumentation and Detectors ,Analytical chemistry ,Physics::Optics ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Chemical vapor deposition ,7. Clean energy ,01 natural sciences ,Electron cyclotron resonance ,Emission ,Condensed Matter::Materials Science ,Materials Science(all) ,Plasma-enhanced chemical vapor deposition ,Quenching ,73.63.Bd ,0103 physical sciences ,General Materials Science ,Silicon oxide ,010302 applied physics ,Quenching (fluorescence) ,Nano Express ,Doping ,Temperature ,78.55.Ap ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,78.67.Bf ,Nanocrystals ,chemistry ,0210 nano-technology ,Erbium - Abstract
Silicon nanocrystals embedded in a silicon-rich silicon oxide matrix doped with Er3+ ions have been fabricated by electron cyclotron resonance plasma-enhanced chemical vapor deposition. Indirect excitation of erbium photoluminescence via silicon nanocrystals has been investigated. Temperature quenching of the photoluminescence originating from the silicon nanocrystals and the erbium ions has been observed. Activation energies of the thermally activated quenching process were estimated for different excitation wavelengths. The temperature quenching mechanism of the emission is discussed. Also, the origin of visible emission and kinetic properties of Er-related emission have been discussed in details.
- Published
- 2013
20. Green light emission from terbium doped silicon rich silicon oxide films obtained by plasma enhanced chemical vapor deposition
- Author
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G. Zatryb, Artur Podhorodecki, Peter Mascher, P. R. J. Wilson, Jacek Wojcik, and Jan Misiewicz
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Photoluminescence ,Materials science ,Silicon ,Physics::Instrumentation and Detectors ,Mechanical Engineering ,Doping ,Analytical chemistry ,Nanocrystalline silicon ,chemistry.chemical_element ,Bioengineering ,Terbium ,General Chemistry ,Rutherford backscattering spectrometry ,Condensed Matter::Materials Science ,chemistry ,Mechanics of Materials ,Plasma-enhanced chemical vapor deposition ,General Materials Science ,Electrical and Electronic Engineering ,Silicon oxide - Abstract
The effect of silicon concentration and annealing temperature on terbium luminescence was investigated for thin silicon rich silicon oxide films. The structures were deposited by means of plasma enhanced chemical vapor deposition. The structural properties of these films were investigated by Rutherford backscattering spectrometry, transmission electron microscopy and Raman scattering. The optical properties were investigated by means of photoluminescence and photoluminescence decay spectroscopy. It was found that both the silicon concentration in the film and the annealing temperature have a strong impact on the terbium emission intensity. In this paper, we present a detailed discussion of these issues and determine the optimal silicon concentration and annealing temperature.
- Published
- 2012
21. Effect of hydrogen passivation on the photoluminescence of Tb ions in silicon rich silicon oxide films
- Author
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Peter Mascher, Jan Misiewicz, M.M. Klak, Artur Podhorodecki, Jacek Wojcik, and G. Zatryb
- Subjects
Materials science ,Photoluminescence ,chemistry ,Hydrogen ,Passivation ,Silicon ,Plasma-enhanced chemical vapor deposition ,General Physics and Astronomy ,chemistry.chemical_element ,Terbium ,Photoluminescence excitation ,Photochemistry ,Silicon oxide - Abstract
In this work, silicon-rich silicon oxide films containing terbium were prepared by means of plasma enhanced chemical vapor deposition. The influence of hydrogen passivation on defects-mediated non-radiative recombination of excited Tb3+ions was investigated by photoluminescence,photoluminescence excitation, and photoluminescence decay measurements. Passivation was found to have no effect on shape and spectral position of the excitation spectra. In contrast, a gradual increase in photoluminescence intensity and photoluminescence decay time was observed upon passivation for the main 5D4-7F5 transition of Tb3+ions. This observation was attributed to passivation of non-radiative recombination defects centers with hydrogen. It was found that the number of emitted photons increases upon passivation as a result of two effects: (1) longer Tb3+ lifetime in the 5D4excited state and (2) optical activation of new Tb3+ emitters. The obtained results were discussed and compared with other experimental reports.
- Published
- 2015
22. Correlation between stress and carrier nonradiative recombination for silicon nanocrystals in an oxide matrix
- Author
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Artur Podhorodecki, Jan Misiewicz, Yansong Shen, Martin A. Green, Xiaojing Hao, and G. Zatryb
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Materials science ,Photoluminescence ,Silicon ,business.industry ,Mechanical Engineering ,Analytical chemistry ,Oxide ,chemistry.chemical_element ,Quantum yield ,Bioengineering ,General Chemistry ,Sputter deposition ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Nanocrystal ,Mechanics of Materials ,symbols ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Spectroscopy ,Raman spectroscopy - Abstract
Silicon nanocrystals embedded in an oxide matrix formed in a multilayer architecture were deposited by the magnetron sputtering method. By means of Raman spectroscopy we have found that compressive stress is exerted on the silicon nanocrystal core. The stress varies as a function of silicon concentration (O/Si ratio) in the silicon-rich oxide (SRO) layers, which can be attributed to the changing nanocrystal environment. By conducting the time-resolved spectroscopy experiment, we demonstrate that, depending on the nanocrystal surroundings, a different amount of nonradiative recombination sites participates in the excited carrier relaxation process, leading to changes of the relative quantum yield of photoluminescence.
- Published
- 2011
23. Temperature dependent emission quenching for silicon nanoclusters
- Author
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Fabrice Gourbilleau, Jan Misiewicz, Artur Podhorodecki, Ch. Dufour, G. Zatryb, Brassy, Chantal, Institute of Physics [Wroclaw], Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Photoluminescence ,Materials science ,[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic ,Silicon ,Biomedical Engineering ,Analytical chemistry ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,Photochemistry ,01 natural sciences ,7. Clean energy ,Spectral line ,Nanoclusters ,Sputtering ,0103 physical sciences ,General Materials Science ,Power density ,010302 applied physics ,General Chemistry ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Photo Luminescence ,chemistry ,Silicon Nanoclusters ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Emission Quenching ,0210 nano-technology ,Excitation - Abstract
International audience; Silicon reach-silicon-oxide (SRSO) film containing silicon nanoclusters was obtained by the reactive magnetron sputtering. Photoluminescence (PL) spectra were measured as a function of temperature at different excitation wavelengths and additionally at different excitation power densities. Obtained PL spectra characterize by two emission bands centered at 1.6 and 2.4 eV. For these bands, temperature behaviour of PL intensities strongly differs but clearly correlate each other. Moreover, it has been observed that obtained PL intensities versus temperature exhibit a strong dependence on the excitation power density in the low temperature range.
- Published
- 2010
24. Quantitative evaluation of boron-induced disorder in multilayers containing silicon nanocrystals in an oxide matrix designed for photovoltaic applications
- Author
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Martin A. Green, Jan Misiewicz, G. Zatryb, Artur Podhorodecki, Xiaojing Hao, and Yansong Shen
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Silicon ,Materials science ,Photoluminescence ,Time Factors ,Photochemistry ,chemistry.chemical_element ,Metal Nanoparticles ,Nanotechnology ,Nanomaterials ,Condensed Matter::Materials Science ,Optics ,Microscopy, Electron, Transmission ,X-Ray Diffraction ,Condensed Matter::Superconductivity ,Photoluminescence excitation ,Boron ,Laplace transform ,business.industry ,Doping ,Oxides ,Equipment Design ,Silicon Dioxide ,Atomic and Molecular Physics, and Optics ,Exponential function ,Kinetics ,Reflection (mathematics) ,chemistry ,Optoelectronics ,business - Abstract
The effect of doping by boron on optical properties of multilayers containing Si-NCs were studied by means of photoluminescence (PL), time-resolved PL, photoluminescence excitation (PLE), transmission and reflection measurements. It was found that PL decay is strongly non-single exponential and can be described by means of Laplace transform of log-normal decay rates distribution. It was also proposed that changes observed in the distribution central moments reflect the disorder induced by boron-doping.
- Published
- 2010
25. Effect of annealing and Nd concentration on the photoluminescence of Nd3+ ions coupled with silicon nanoparticles
- Author
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Jan Misiewicz, Christophe Labbé, G. Zatryb, Artur Podhorodecki, Fabrice Gourbilleau, D. Bréard, Julien Cardin, Olivier Debieu, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Institute of Physics [Wroclaw], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
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010302 applied physics ,Materials science ,Photoluminescence ,Silicon ,Annealing (metallurgy) ,Analytical chemistry ,General Physics and Astronomy ,Infrared spectroscopy ,chemistry.chemical_element ,02 engineering and technology ,Sputter deposition ,021001 nanoscience & nanotechnology ,7. Clean energy ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry ,Sputtering ,0103 physical sciences ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Fourier transform infrared spectroscopy ,Thin film ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,0210 nano-technology - Abstract
International audience; We report on the microstructure and photoluminescence (PL) properties of Nd-doped SiO2 thin films containing silicon nanoparticles (Si-np) as a function of the annealing temperature and the Nd concentration. The thin films, which were grown on Si substrates by reactive magnetron co-sputtering, contain the same Si excess. Fourier transform infrared (FTIR) spectra show that a phase separation occurs during the annealing due to the agglomeration of the Si excess resulting in the formation of Si-np. Besides, after annealing, the films exhibit PL from excitonic states confined in Si-np. We showed that the intensity of the PL of Nd3+ ions that occurs at ~0.92, 1.06, and 1.4 µm is maximal at low Nd concentration and while well-passivated Si-np are formed. FTIR and x-ray measurements showed that the increase in the Nd incorporation has detrimental effects on the PL of Nd3+ because of the formation of Nd2O3 nanocrystals and inherent disorder in the SiO2 host matrix. PL excitation measurements demonstrate that the PL of Nd3+ ions is nonresonant and follows the excitation of Si-np giving new evidence of the energy transfer from Si-np toward the rare earth ions.
- Published
- 2010
26. Effects of Si-rich oxide layer stoichiometry on the structural and optical properties of Si QD/SiO2 multilayer films
- Author
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J. Misiewicz, Yansong Shen, G. Zatryb, Martin A. Green, Artur Podhorodecki, and Xiaojing Hao
- Subjects
Materials science ,Photoluminescence ,Annealing (metallurgy) ,Mechanical Engineering ,Analytical chemistry ,Oxide ,Bioengineering ,General Chemistry ,chemistry.chemical_compound ,Absorption edge ,chemistry ,Mechanics of Materials ,Quantum dot ,Transmission electron microscopy ,General Materials Science ,Photoluminescence excitation ,Electrical and Electronic Engineering ,Stoichiometry - Abstract
The effects of the stoichiometry of the Si-rich oxide (SRO) layer, O/Si ratio, on the structural and optical properties of SRO/SiO2 multilayer films were investigated in this work. SRO/SiO2 multilayer films with different O/Si ratios were grown by a co-sputtering technique, and Si quantum dots (QDs) were formed with post-deposition annealing. By transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD), it was found that the Si QD size decreases with increases in O/Si ratio. The photoluminescence (PL) spectrum varies with the O/Si ratio in band position, shape and intensity. In addition, it was observed that the absorption edge blue-shifts with increases in the O/Si ratio. The change in the absorption edge is consistent with strengthening quantum confinement effects in Si QDs, as indicated by TEM and GIXRD. The optical properties were also investigated by 2D photoluminescence excitation (2D-PLE) and lifetime measurements. The origin of emission and absorption is discussed based on the absorption, PL, 2D-PLE and decay time measurements.
- Published
- 2009
27. Size-Dependent Indirect Excitation of Trivalent Er Ions via Si Nanocrystals Embedded in a Silicon-Rich Silicon Oxide Matrix Deposited by ECR-PECVD
- Author
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Jacek Wojcik, Jan Misiewicz, Artur Podhorodecki, Peter Mascher, and G. Zatryb
- Subjects
Materials science ,Photoluminescence ,Silicon ,Article Subject ,business.industry ,Inorganic chemistry ,Nanocrystalline silicon ,chemistry.chemical_element ,Chemical vapor deposition ,Erbium ,chemistry ,Nanocrystal ,Plasma-enhanced chemical vapor deposition ,lcsh:Technology (General) ,Optoelectronics ,lcsh:T1-995 ,General Materials Science ,business ,Silicon oxide - Abstract
Silicon nanocrystals (Si-nc) embedded in a silicon-rich silicon oxide matrix codoped withEr3+ions have been fabricated by electron-cyclotron plasma-enhanced chemical vapor deposition. Indirect excitation of erbium photoluminescence via silicon nanocrystals has been obtained within a broad pump wavelength range. The influence of different nanocrystal sizes on the excitation transfer from the Si-nc toEr3+ions is discussed.
- Published
- 2009
28. Excitation mechanism and thermal emission quenching of Tb ions in silicon rich silicon oxide thin films grown by plasma-enhanced chemical vapour deposition—Do we need silicon nanoclusters?
- Author
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K. Fedus, P. R. J. Wilson, G. Zatryb, Jacek Wojcik, Artur Podhorodecki, Peter Mascher, J. Wang, Jan Misiewicz, L W Golacki, and Wojciech M. Jadwisienczak
- Subjects
Materials science ,Photoluminescence ,Silicon ,chemistry ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Cathodoluminescence ,Chemical vapor deposition ,Thin film ,Fourier transform infrared spectroscopy ,Silicon oxide ,Rutherford backscattering spectrometry - Abstract
In this work, we will discuss the excitation and emission properties of Tb ions in a Silicon Rich Silicon Oxide (SRSO) matrix obtained at different technological conditions. By means of electron cyclotron resonance plasma-enhanced chemical vapour deposition, undoped and doped SRSO films have been obtained with different Si content (33, 35, 39, 50 at. %) and were annealed at different temperatures (600, 900, 1100 °C). The samples were characterized optically and structurally using photoluminescence (PL), PL excitation, time resolved PL, absorption, cathodoluminescence, temperature dependent PL, Rutherford backscattering spectrometry, Fourier transform infrared spectroscopy and positron annihilation lifetime spectroscopy. Based on the obtained results, we discuss how the matrix modifications influence excitation and emission properties of Tb ions.
- Published
- 2014
29. Ion–ion interaction in two-dimensional nanoporous alumina filled with cubic YAlO3 : Tb3+matrix
- Author
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L W Golacki, Artur Podhorodecki, L. S. Khoroshko, N. V. Gaponenko, Jan Misiewicz, George Thompson, Marcin Motyka, Jarosław Serafińczuk, I. S. Molchan, and G. Zatryb
- Subjects
Photoluminescence ,Materials science ,Acoustics and Ultrasonics ,Silicon ,Nanoporous ,Doping ,Analytical chemistry ,chemistry.chemical_element ,Terbium ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,chemistry ,Phase (matter) ,Excitation - Abstract
Terbium doped YAlO3 composites, with terbium concentrations up to 2.11 at%, were fabricated by co-precipitation in porous anodic alumina films grown on silicon. The presence of the cubic YAlO3 phase was confirmed by x-ray diffraction and FT-IR analysis. The fabricated samples demonstrate photoluminescence (PL) within the range 350?640?nm, which is associated with f?f transitions from the 5D3, 5G6 and 5D4 levels of Tb3+ ion. Additionally, a broad and fast- decaying PL band in the blue range has been observed, which is associated with defect states. Based on PL excitation spectra, the main excitation channel of Tb3+ ions is due to 4f?5d transitions. Excitation bands observed at 235, 270 and 320?nm have been related to the permitted low-spin 5d2 [LS], 5d1 [LS] and forbidden high-spin 5d1 [HS] states, respectively. The PL decay spectra have been measured, with the results analysed using the maximum entropy method; a strong indication of ion?ion interaction has been observed. The distribution of Tb3+ ions in the PAA?:?YAlO3 structure has been proposed and its influence on optical properties of Tb3+ ions has been discussed.
- Published
- 2013
30. On the nature of the stretched exponential photoluminescence decay for silicon nanocrystals
- Author
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G. Zatryb, Artur Podhorodecki, Fabrice Gourbilleau, J. Misiewicz, Julien Cardin, Institute of Physics, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Stretched exponential function ,Materials science ,Photoluminescence ,Hydrogen ,Nanochemistry ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,01 natural sciences ,Molecular physics ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Condensed Matter::Materials Science ,Materials Science(all) ,Sputtering ,0103 physical sciences ,lcsh:TA401-492 ,General Materials Science ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Spectroscopy ,010302 applied physics ,Nano Express ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Exponential function ,Reflection (mathematics) ,chemistry ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology - Abstract
The influence of hydrogen rate on optical properties of silicon nanocrystals deposited by sputtering method was studied by means of time-resolved photoluminescence spectroscopy as well as transmission and reflection measurements. It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function. It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm. Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.
- Published
- 2011
31. Influence of Europium Concentration on Optical and Structural Properties of Nanocrystalline GaN:Eu[sup 3+] Powder
- Author
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Jan Misiewicz, G. Zatryb, Marcin Nyk, Artur Podhorodecki, and Wieslaw Strek
- Subjects
Diffraction ,Materials science ,Dopant ,General Chemical Engineering ,Doping ,Analytical chemistry ,chemistry.chemical_element ,Spectral line ,Nanocrystalline material ,Ion ,chemistry ,Nanocrystal ,Electrochemistry ,General Materials Science ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Europium - Abstract
In this work, GaN nanocrystals doped by europium (III) ions at different concentrations have been synthesized by modified nitridation method at 1050°C temperature. From X-ray diffraction spectra, it has been found that the size of nanocrystals strongly depends on the dopant concentration in a nonlinear way and varying from ∼ 20 up to 35 nm when the europium concentration varies from 0.5 up to 2 mol %. Moreover, it has been found that obtained nanocrystals are characterized by two main emission bands, one related to GaN core (∼ 364 nm) and the second to surface/defect states (∼ 600 nm). It has been shown that the relative intensity of these bands varies with changing of the europium concentration due to changes of GaN nanocrystals surface-to-volume ratio.
- Published
- 2009
32. Influence of the annealing temperature and silicon concentration on the absorption and emission properties of Si nanocrystals
- Author
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Jan Misiewicz, Peter Mascher, G. Zatryb, Artur Podhorodecki, and Jacek Wojcik
- Subjects
Photoluminescence ,Materials science ,Absorption edge ,Nanocrystal ,Silicon ,chemistry ,Annealing (metallurgy) ,Analytical chemistry ,Transmittance ,General Physics and Astronomy ,Infrared spectroscopy ,chemistry.chemical_element ,Chemical vapor deposition - Abstract
Silicon nanocrystals embedded in a silicon-rich silicon-oxide matrix have been fabricated at different silicon contents (38%, 40%, and 49%) using plasma-enhanced chemical vapor deposition and annealing at different temperatures in the range from 900 °C to 1100 °C. Their optical properties have been investigated by photoluminescence and transmittance measurements. Strong, room-temperature emission bands at ∼1.6 eV have been observed for all samples, with intensities dependent on the annealing temperature and Si content of the samples. From transmittance measurements, a redshift of the absorption edge has been detected when increasing the annealing temperature or Si content.
- Published
- 2007
33. Correlation between matrix structural order and compressive stress exerted on silicon nanocrystals embedded in silicon-rich silicon oxide
- Author
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Jan Misiewicz, Julien Cardin, G. Zatryb, Fabrice Gourbilleau, Artur Podhorodecki, Institute of Physics, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Silicon ,Materials science ,chemistry.chemical_element ,Infrared spectroscopy ,Nanotechnology ,02 engineering and technology ,Stress ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Stress (mechanics) ,symbols.namesake ,Materials Science(all) ,Sputtering ,0103 physical sciences ,Disorder ,Phonon ,General Materials Science ,7425Nd ,Composite material ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Silicon oxide ,7363Bd ,Raman ,010302 applied physics ,Nano Express ,Matrix ,Nanocrystalline silicon ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,7867Pt ,Nanocrystals ,chemistry ,Nanocrystal ,symbols ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Matrix PACS: 7867Bf ,7847D ,Order ,0210 nano-technology ,Raman spectroscopy ,Confinement - Abstract
Abstract Silicon nanocrystals embedded in a silicon oxide matrix were deposited by radio frequency reactive magnetron sputtering. By means of Raman spectroscopy, we have found that a compressive stress is exerted on the silicon nanocrystal cores. The stress varies as a function of silicon concentration in the silicon-rich silicon oxide layers varies, which can be attributed to changes of nanocrystal environment. By conducting the Fourier transform infrared absorption experiments, we have correlated the stresses exerted on the nanocrystal core to the degree of matrix structural order. PACS 78.67.Bf, 78.67.Pt, 73.63.Bd, 78.47.D, 74.25.Nd
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34. Correlation between stress and carrier nonradiative recombination for silicon nanocrystals in an oxide matrix.
- Author
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G Zatryb, A Podhorodecki, X J Hao, J Misiewicz, Y S Shen, and M A Green
- Subjects
- *
SILICON , *NANOCRYSTALS , *MULTILAYERED thin films , *MAGNETRON sputtering , *STATISTICAL correlation , *PHOTOLUMINESCENCE , *STRAINS & stresses (Mechanics) , *OXIDES - Abstract
Silicon nanocrystals embedded in an oxide matrix formed in a multilayer architecture were deposited by the magnetron sputtering method. By means of Raman spectroscopy we have found that compressive stress is exerted on the silicon nanocrystal core. The stress varies as a function of silicon concentration (O/Si ratio) in the silicon-rich oxide (SRO) layers, which can be attributed to the changing nanocrystal environment. By conducting the time-resolved spectroscopy experiment, we demonstrate that, depending on the nanocrystal surroundings, a different amount of nonradiative recombination sites participates in the excited carrier relaxation process, leading to changes of the relative quantum yield of photoluminescence. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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35. Effects of Si-rich oxide layer stoichiometry on the structural and optical properties of Si QD/SiO2 multilayer films.
- Author
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X J Hao, A P Podhorodecki, Y S Shen, G Zatryb, J Misiewicz, and M A Green
- Subjects
STOICHIOMETRY ,SILICON oxide ,MOLECULAR structure ,MULTILAYERED thin films ,OPTICAL properties ,THIN films ,QUANTUM dots ,CRYSTAL growth ,SPUTTERING (Physics) - Abstract
The effects of the stoichiometry of the Si-rich oxide (SRO) layer, O/Si ratio, on the structural and optical properties of SRO/SiO2 multilayer films were investigated in this work. SRO/SiO2 multilayer films with different O/Si ratios were grown by a co-sputtering technique, and Si quantum dots (QDs) were formed with post-deposition annealing. By transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD), it was found that the Si QD size decreases with increases in O/Si ratio. The photoluminescence (PL) spectrum varies with the O/Si ratio in band position, shape and intensity. In addition, it was observed that the absorption edge blue-shifts with increases in the O/Si ratio. The change in the absorption edge is consistent with strengthening quantum confinement effects in Si QDs, as indicated by TEM and GIXRD. The optical properties were also investigated by 2D photoluminescence excitation (2D-PLE) and lifetime measurements. The origin of emission and absorption is discussed based on the absorption, PL, 2D-PLE and decay time measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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36. The influence of solvent refractive index on the photoluminescence decay of thick-shell gradient-alloyed colloidal quantum dots investigated in a wide range of delay times.
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Zatryb G, Adamski A, Chrzanowski M, Żak AM, and Podhorodecki A
- Subjects
- Refractometry, Luminescent Measurements, Semiconductors, Time Factors, Quantum Dots chemistry, Solvents chemistry, Luminescence, Colloids chemistry
- Abstract
Colloidal semiconductor quantum dots have many potential optical applications, including quantum dot light-emitting diodes, single-photon sources, or biological luminescent markers. The optical properties of colloidal quantum dots can be affected by their dielectric environment. This study investigated the photoluminescence (PL) decay of thick-shell gradient-alloyed colloidal semiconductor quantum dots as a function of solvent refractive index. These measurements were conducted in a wide range of delay times to account for both the initial spontaneous decay of excitons and the delayed emission of excitons that has the form of a power law. It is shown that whereas the initial spontaneous PL decay is very sensitive to the refractive index of the solvent, the power-law delayed emission of excitons is not. Our results seem to exclude the possibility of carrier self-trapping in the considered solvents and suggest the existence of trap states inside the quantum dots. Finally, our data show that the average exciton lifetime significantly decreases as a function of the solvent refractive index. The change in exciton lifetime is qualitatively modeled and discussed., (© 2024 John Wiley & Sons Ltd.)
- Published
- 2024
- Full Text
- View/download PDF
37. Effect of Air Exposure of ZnMgO Nanoparticle Electron Transport Layer on Efficiency of Quantum-Dot Light-Emitting Diodes.
- Author
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Chrzanowski M, Zatryb G, Sitarek P, and Podhorodecki A
- Abstract
We demonstrate the effect of air exposure on optical and electrical properties of ZnMgO nanoparticles (NPs) typically exploited as an electron transport layer in Cd-based quantum-dot light-emitting diodes (QLEDs). We analyze the roles of air components in modifying the electrical properties of ZnMgO NPs, which reveals that H
2 O enables the reduction of hole leakage while O2 alters the character of charge transport due to its ability to trap electrons. As a result, the charge balance in the QDs layer is improved, which is confirmed by voltage-dependent measurements of photoluminescence quantum yield. The maximum external quantum efficiency is improved over 2-fold and reaches the value of 9.5% at a luminance of 104 cd/m2 . In addition, we investigate the problem of electron leakage into the hole transport layer and show that trap-mediated electron transport in the ZnMgO layer caused by adsorbed O2 ensures a higher leakage threshold. This work also provides an insight into the possible disadvantages of device contact with air as well as problems and challenges that might occur during open-air fabrication of QLEDs.- Published
- 2021
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38. On the choice of proper average lifetime formula for an ensemble of emitters showing non-single exponential photoluminescence decay.
- Author
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Zatryb G and Klak MM
- Abstract
In this paper, we investigate non-single exponential photoluminescence decays in various disordered condensed-matter systems. For such materials, two formulas for the average lifetime of system's excited state are commonly used in the analysis of experimental data. In many cases, the choice of formula is arbitrary and lacks a clear physical justification. For this reason, our main goal is to show that the choice of correct mathematical formula should be based on the interpretation of measured photoluminescence decay curve. It is shown that depending on the investigated system, after appropriate normalization, photoluminescence decay curve can represent either a survival probability function or a probability density function of lifetime and for this reason two different formulas for the average lifetime are required. It is also shown that, depending on luminescence quantum yield, some information on the probability density function of lifetime can be lost in the process of measurement, which results in underestimated values of average lifetime. Finally, we provide an interpretation of total decay rate distributions which are frequently obtained by phenomenological modeling of non-single exponential photoluminescence decays., (Creative Commons Attribution license.)
- Published
- 2020
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39. Enhanced photoluminescence stability of CdS nanocrystals through a zinc acetate reagent.
- Author
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Banski M, Chrzanowski M, Zatryb G, Misiewicz J, and Podhorodecki A
- Abstract
In this study, the role of a zinc acetate precursor in improving the luminescence stability of purple-emitting CdS nanocrystals is investigated. The oleate-capped core of CdS nanocrystals exhibits intense photodarkening under prolonged UV excitation. From the results of photoluminescence experiments, we can observe that photobleaching is responsible for the degradation of temporal stability, i.e. , decline in photoluminescence intensity. Herein, we demonstrate that by adding zinc acetate to the synthesis solution, one can enhance the photoluminescence stability by the complete suppression of the bleaching processes of nanocrystals. We can distinguish between the effects caused by zinc ions and those caused by acetate ligands. Acetate ligands improve the photoluminescence stability of the core of CdS nanocrystals. However, only when zinc acetate is used, the PL stability can be conserved at high excitation power. Simultaneously, we have studied the influence of zinc cations and acetate ligands on the kinetics of nanocrystal growth. The presented results underline the importance of short surface capping ligands and zinc cations in CdS nanocrystal synthesis. This study exhibits a new advantage of exploiting zinc acetate reagents in one-pot nanocrystal synthesis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
- Published
- 2018
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40. Structural and emission properties of Tb 3+ -doped nitrogen-rich silicon oxynitride films.
- Author
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Labbé C, An YT, Zatryb G, Portier X, Podhorodecki A, Marie P, Frilay C, Cardin J, and Gourbilleau F
- Abstract
Terbium doped silicon oxynitride host matrix is suitable for various applications such as light emitters compatible with CMOS technology or frequency converter systems for photovoltaic cells. In this study, amorphous Tb
3+ ion doped nitrogen-rich silicon oxynitride (NRSON) thin films were fabricated using a reactive magnetron co-sputtering method, with various N2 flows and annealing conditions, in order to study their structural and emission properties. Rutherford backscattering (RBS) measurements and refractive index values confirmed the silicon oxynitride nature of the films. An electron microscopy analysis conducted for different annealing temperatures (TA ) was also performed up to 1200 °C. Transmission electron microscopy (TEM) images revealed two different sublayers. The top layer showed porosities coming from a degassing of oxygen during deposition and annealing, while in the region close to the substrate, a multilayer-like structure of SiO2 and Si3 N4 phases appeared, involving a spinodal decomposition. Upon a 1200 °C annealing treatment, a significant density of Tb clusters was detected, indicating a higher thermal threshold of rare earth (RE) clusterization in comparison to the silicon oxide matrix. With an opposite variation of the N2 flow during the deposition, the nitrogen excess parameter (Nex ) estimated by RBS measurements was introduced to investigate the Fourier transform infrared (FTIR) spectrum behavior and emission properties. Different vibration modes of the Si-N and Si-O bonds have been carefully identified from the FTIR spectra characterizing such host matrices, especially the 'out-of-phase' stretching vibration mode of the Si-O bond. The highest Tb3+ photoluminescence (PL) intensity was obtained by optimizing the N incorporation and the annealing conditions. In addition, according to these conditions, the integrated PL intensity variation confirmed that the silicon nitride-based host matrix had a higher thermal threshold of rare earth clusterization than its silicon oxide counterpart. Analysis of time-resolved PL intensity versus TA showed the impact of Tb clustering on decay times, in agreement with the TEM observations. Finally, PL and PL excitation (PLE) experiments and comparison of the related spectra between undoped and Tb-doped samples were carried out to investigate the impact of the band tails on the excitation mechanism of Tb3+ ions.- Published
- 2017
- Full Text
- View/download PDF
41. On the origin of emission and thermal quenching of SRSO:Er3+ films grown by ECR-PECVD.
- Author
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Podhorodecki A, Zatryb G, Golacki LW, Misiewicz J, Wojcik J, and Mascher P
- Abstract
Silicon nanocrystals embedded in a silicon-rich silicon oxide matrix doped with Er3+ ions have been fabricated by electron cyclotron resonance plasma-enhanced chemical vapor deposition. Indirect excitation of erbium photoluminescence via silicon nanocrystals has been investigated. Temperature quenching of the photoluminescence originating from the silicon nanocrystals and the erbium ions has been observed. Activation energies of the thermally activated quenching process were estimated for different excitation wavelengths. The temperature quenching mechanism of the emission is discussed. Also, the origin of visible emission and kinetic properties of Er-related emission have been discussed in details.
- Published
- 2013
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42. Correlation between matrix structural order and compressive stress exerted on silicon nanocrystals embedded in silicon-rich silicon oxide.
- Author
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Zatryb G, Podhorodecki A, Misiewicz J, Cardin J, and Gourbilleau F
- Abstract
Silicon nanocrystals embedded in a silicon oxide matrix were deposited by radio frequency reactive magnetron sputtering. By means of Raman spectroscopy, we have found that a compressive stress is exerted on the silicon nanocrystal cores. The stress varies as a function of silicon concentration in the silicon-rich silicon oxide layers varies, which can be attributed to changes of nanocrystal environment. By conducting the Fourier transform infrared absorption experiments, we have correlated the stresses exerted on the nanocrystal core to the degree of matrix structural order. PACS: 78.67.Bf, 78.67.Pt, 73.63.Bd, 78.47.D, 74.25.Nd.
- Published
- 2013
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43. Green light emission from terbium doped silicon rich silicon oxide films obtained by plasma enhanced chemical vapor deposition.
- Author
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Podhorodecki A, Zatryb G, Misiewicz J, Wojcik J, Wilson PR, and Mascher P
- Abstract
The effect of silicon concentration and annealing temperature on terbium luminescence was investigated for thin silicon rich silicon oxide films. The structures were deposited by means of plasma enhanced chemical vapor deposition. The structural properties of these films were investigated by Rutherford backscattering spectrometry, transmission electron microscopy and Raman scattering. The optical properties were investigated by means of photoluminescence and photoluminescence decay spectroscopy. It was found that both the silicon concentration in the film and the annealing temperature have a strong impact on the terbium emission intensity. In this paper, we present a detailed discussion of these issues and determine the optimal silicon concentration and annealing temperature.
- Published
- 2012
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44. Correlation between stress and carrier nonradiative recombination for silicon nanocrystals in an oxide matrix.
- Author
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Zatryb G, Podhorodecki A, Hao XJ, Misiewicz J, Shen YS, and Green MA
- Abstract
Silicon nanocrystals embedded in an oxide matrix formed in a multilayer architecture were deposited by the magnetron sputtering method. By means of Raman spectroscopy we have found that compressive stress is exerted on the silicon nanocrystal core. The stress varies as a function of silicon concentration (O/Si ratio) in the silicon-rich oxide (SRO) layers, which can be attributed to the changing nanocrystal environment. By conducting the time-resolved spectroscopy experiment, we demonstrate that, depending on the nanocrystal surroundings, a different amount of nonradiative recombination sites participates in the excited carrier relaxation process, leading to changes of the relative quantum yield of photoluminescence.
- Published
- 2011
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- View/download PDF
45. On the nature of the stretched exponential photoluminescence decay for silicon nanocrystals.
- Author
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Zatryb G, Podhorodecki A, Misiewicz J, Cardin J, and Gourbilleau F
- Abstract
The influence of hydrogen rate on optical properties of silicon nanocrystals deposited by sputtering method was studied by means of time-resolved photoluminescence spectroscopy as well as transmission and reflection measurements. It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function. It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm. Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.
- Published
- 2011
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46. Quantitative evaluation of boron-induced disorder in multilayers containing silicon nanocrystals in an oxide matrix designed for photovoltaic applications.
- Author
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Zatryb G, Podhorodecki A, Hao XJ, Misiewicz J, Shen YS, and Green MA
- Subjects
- Equipment Design instrumentation, Equipment Design methods, Kinetics, Microscopy, Electron, Transmission methods, Photochemistry methods, Silicon Dioxide chemistry, Time Factors, X-Ray Diffraction methods, Boron chemistry, Metal Nanoparticles chemistry, Nanotechnology methods, Oxides chemistry, Silicon chemistry
- Abstract
The effect of doping by boron on optical properties of multilayers containing Si-NCs were studied by means of photoluminescence (PL), time-resolved PL, photoluminescence excitation (PLE), transmission and reflection measurements. It was found that PL decay is strongly non-single exponential and can be described by means of Laplace transform of log-normal decay rates distribution. It was also proposed that changes observed in the distribution central moments reflect the disorder induced by boron-doping.
- Published
- 2010
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47. Temperature dependent emission quenching for silicon nanoclusters.
- Author
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Podhorodecki A, Zatryb G, Misiewicz J, Gourbilleau F, and Dufour C
- Abstract
Silicon reach-silicon-oxide (SRSO) film containing silicon nanoclusters was obtained by the reactive magnetron sputtering. Photoluminescence (PL) spectra were measured as a function of temperature at different excitation wavelengths and additionally at different excitation power densities. Obtained PL spectra characterize by two emission bands centered at 1.6 and 2.4 eV. For these bands, temperature behaviour of PL intensities strongly differs but clearly correlate each other. Moreover, it has been observed that obtained PL intensities versus temperature exhibit a strong dependence on the excitation power density in the low temperature range.
- Published
- 2010
- Full Text
- View/download PDF
48. Effects of Si-rich oxide layer stoichiometry on the structural and optical properties of Si QD/SiO2 multilayer films.
- Author
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Hao XJ, Podhorodecki AP, Shen YS, Zatryb G, Misiewicz J, and Green MA
- Abstract
The effects of the stoichiometry of the Si-rich oxide (SRO) layer, O/Si ratio, on the structural and optical properties of SRO/SiO2 multilayer films were investigated in this work. SRO/SiO2 multilayer films with different O/Si ratios were grown by a co-sputtering technique, and Si quantum dots (QDs) were formed with post-deposition annealing. By transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD), it was found that the Si QD size decreases with increases in O/Si ratio. The photoluminescence (PL) spectrum varies with the O/Si ratio in band position, shape and intensity. In addition, it was observed that the absorption edge blue-shifts with increases in the O/Si ratio. The change in the absorption edge is consistent with strengthening quantum confinement effects in Si QDs, as indicated by TEM and GIXRD. The optical properties were also investigated by 2D photoluminescence excitation (2D-PLE) and lifetime measurements. The origin of emission and absorption is discussed based on the absorption, PL, 2D-PLE and decay time measurements.
- Published
- 2009
- Full Text
- View/download PDF
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