scholarly journals Dependence of optical properties of calcium bismuthates on synthesis conditions

2016 ◽  
Vol 735 ◽  
pp. 012068 ◽  
Author(s):  
D S Shtarev ◽  
A V Shtareva
Keyword(s):  
Optical Properties ◽  
Synthesis Conditions

scholarly journals Synthesis conditions influencing formation of MAPbBr3 perovskite nanoparticles prepared by the ligand-assisted precipitation method

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Jancik Prochazkova ◽  
Markus Clark Scharber ◽  
Cigdem Yumusak ◽  
Ján Jančík ◽  
Jiří Másilko ◽  
...  
Keyword(s):  
Optical Properties ◽  
Colloidal Stability ◽  
Precursor Solution ◽  
Solvent System ◽  
Precipitation Method ◽  
Colloidal Solutions ◽  
Capping Agents ◽  
Synthesis Conditions ◽  
Perovskite Nanoparticles ◽  
Selection Of

Abstract This work reports on an optimized procedure to synthesize methylammonium bromide perovskite nanoparticles. The ligand-assisted precipitation synthetic pathway for preparing nanoparticles is a cost-effective and promising method due to its ease of scalability, affordable equipment requirements and convenient operational temperatures. Nevertheless, there are several parameters that influence the resulting optical properties of the final nanomaterials. Here, the influence of the choice of solvent system, capping agents, temperature during precipitation and ratios of precursor chemicals is described, among other factors. Moreover, the colloidal stability and stability of the precursor solution is studied. All of the above-mentioned parameters were observed to strongly affect the resulting optical properties of the colloidal solutions. Various solvents, dispersion media, and selection of capping agents affected the formation of the perovskite structure, and thus qualitative and quantitative optimization of the synthetic procedure conditions resulted in nanoparticles of different dimensions and optical properties. The emission maxima of the nanoparticles were in the 508–519 nm range due to quantum confinement, as confirmed by transmission electron microscopy. This detailed study allows the selection of the best optimal conditions when using the ligand-assisted precipitation method as a powerful tool to fine-tune nanostructured perovskite features targeted for specific applications.

scholarly journals NaYF4 Microstructure, beyond Their Well-Shaped Morphology

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1560
Author(s):  
Godefroy Leménager ◽  
Sandrine Tusseau-Nenez ◽  
Maud Thiriet ◽  
Pierre-Eugène Coulon ◽  
Khalid Lahlil ◽  
...  
Keyword(s):  
Optical Properties ◽  
Local Symmetry ◽  
Xrd Analysis ◽  
Lanthanide Ions ◽  
Strong Variation ◽  
Emission Analysis ◽  
Synthesis Conditions ◽  
Polarized Emission ◽  
Local Deviation ◽  
Crystalline Symmetry

Lanthanide-doped nanoparticles are widely investigated for their optical properties. However, the sensitivity of the lanthanide ions’ luminescence to the local symmetry, useful when investigating structural environments, becomes a drawback for optimized properties in the case of poorly controlled crystallinity. In this paper, we focus on β -NaYF4 nanorods in order to provide a detailed description of their chemical composition and microstructure. The combination of detailed XRD analysis and TEM observations show that strong variation may be observed from particles from a same batch of synthesis, but also when considering small variations of synthesis conditions. Moreover, also the nanorods observed by SEM exhibit a very nice faceted shape, they are far from being monocrystalline and present significant local deviation of crystalline symmetry and orientation. All these structural considerations, sensitively probed by polarized emission analysis, are crucial to analyze for the development of optimal systems toward the targeted applications.

scholarly journals THE OPTICAL PROPERTIES OF MULTILAYER PERIODIC STRUCTURES BaTiO3:Eu/SiO2

Doklady BGUIR ◽  
2019 ◽  
pp. 95-100
Author(s):  
D. A. Parafinyuk ◽  
N. V. Gaponenko ◽  
T. F. Raichenok
Keyword(s):  
Optical Properties ◽  
Periodic Structures ◽  
Photonic Band Gap ◽  
Bragg Reflector ◽  
Wavelength Shift ◽  
Excitation Spectra ◽  
Synthesis Conditions ◽  
Long Wavelength ◽  
Kinetics Of ◽  
Photonic Band

This paper presents the study of the optical properties of multilayer periodic structures, such as Bragg reflector, with different synthesis conditions. Transmission, reflection, luminescence, luminescence excitation spectra and kinetics of luminescence are presented for the Bragg reflectors formed on quartz with 6 and 12 alternating layers BaTiO3:Eu/SiO2. The structures demonstrate photonic band gap and its long wavelength shift with increasing number of layers. Europium luminescence with the most intensive band at 615 nm is observed from the structures. A decrease in the luminescence intensity with increasing the number of pairs of the layers in the structure is observed.

scholarly journals Атомная структура и оптические свойства слоев CaSi-=SUB=-2-=/SUB=-, выращенных на CaF-=SUB=-2-=/SUB=-/Si-подложках

2021 ◽  
Vol 55 (9) ◽  
pp. 725
Author(s):  
В.А. Зиновьев ◽  
А.В. Кацюба ◽  
В.А. Володин ◽  
А.Ф. Зиновьева ◽  
С.Г. Черкова ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electron Beam ◽  
High Energy ◽  
Two Dimensional ◽  
High Energy Electron ◽  
Photoluminescence Spectra ◽  
Structural And Optical Properties ◽  
Synthesis Conditions ◽  
Simultaneous Irradiation ◽  
Growth Features

In this work, we study the growth features, as well as the structural and optical properties of CaSi2 layers formed in the process of successive deposition of Si and CaF2 on a Si (111) substrate with simultaneous irradiation with high energy electron beam. The Raman spectra recorded in the regions of the electron beam action showed peaks characteristic of crystalline CaSi2 layers. The study of the surface morphology of the grown structures demonstrated that, under the chosen synthesis conditions, the formation of CaSi2 layers during electron irradiation occurs according to a two-dimensional layer mechanism. The photoluminescence spectra measured in the region modified by the electron beam have significant differences from the spectra measured outside this region.

The Effect of Nonequilibrium Synthesis Conditions on the Structure and Optical Properties of Amorphous Carbon Films

2019 ◽  
Vol 127 (2) ◽  
pp. 251-259 ◽  
Author(s):  
A. P. Ryaguzov ◽  
R. R. Nemkayeva ◽  
O. I. Yukhnovets ◽  
N. R. Guseinov ◽  
S. L. Mikhailova ◽  
...  
Keyword(s):  
Optical Properties ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
Synthesis Conditions

Cunning defects: emission control by structural point defects on Cu(i)I double chain coordination polymers

2020 ◽  
Vol 8 (4) ◽  
pp. 1448-1458 ◽  
Author(s):  
Javier Conesa-Egea ◽  
Javier González-Platas ◽  
Ulises R. Rodríguez-Mendoza ◽  
José Ignacio Martínez ◽  
Ocon Pilar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Coordination Polymers ◽  
Point Defects ◽  
Emission Control ◽  
Double Chain ◽  
Synthesis Conditions ◽  
Identical Structure ◽  
Structural Point

We present two new coordination polymers based on double Cu(i)–I chains, with identical structure. Variations in the synthesis conditions lead to the formation of defects which strongly affect the optical properties of these compounds.

scholarly journals Effect of Deposition Parameters on Kinematics Growth and Optical Properties of PbS Nano Films Deposited by Chemical Bath Deposition

2014 ◽  
Vol 34 ◽  
pp. 1-10 ◽  
Author(s):  
Ali M. Mousa ◽  
Slma M. Hassen ◽  
S. Mohmoed
Keyword(s):  
Growth Rate ◽  
Optical Properties ◽  
Energy Range ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Deposition Time ◽  
Ph Value ◽  
Bath Temperature ◽  
Synthesis Conditions ◽  
Deposition Parameters

The paper presents a study regarding the kinetic of chemical bath deposition (CBD) PbS nano films. Nano films were deposited from chemical bath containing thiourea, lead nitrite, and ammonia. The deposition kinematics and optical investigations have been performed to compare the properties of the films grown with different precursor solutions. We are able to determine the growth rate as a function of the synthesis conditions and it was found that the growth rate of deposited nano layer affected significantly by synthesis conditions. The main characteristic of nano films is the band gap. This parameter determined from spectroscopy Measurements of transmission, in the energy range of 240-840 nm is influenced by many factors such as deposition time, bath temperature, pH value of the path and molar concentration of the reactants.

Correlation between the electrochemical synthesis conditions and the optical properties of polypyrrole

1997 ◽  
Vol 84 (1-3) ◽  
pp. 825-826 ◽  
Author(s):  
R. Turcu ◽  
M. Brie ◽  
G. Leising ◽  
A. Niko ◽  
V. Tosa ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electrochemical Synthesis ◽  
Synthesis Conditions

scholarly journals Effect of Precursor Nature and Sol-Gel Synthesis Conditions on TiO2 Aerogel’s Structure

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5090
Author(s):  
Jolanta Doneliene ◽  
Egle Fataraite-Urboniene ◽  
Matas Rudzikas ◽  
Saulius Pakalka ◽  
Nina Danchova ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Parameters ◽  
Anatase Phase ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Drying Methods ◽  
High Porosity ◽  
Structural And Optical Properties ◽  
Synthesis Conditions ◽  
Sol Gel Synthesis

The aim of this investigation was to synthesize high porosity TiO2 aerogel by applying sol-gel and subcritical drying methods and to identify the influence of reagent’s nature and synthesis conditions on their structural and optical properties. Methods of XRD, FT-IR, BET, STA, SEM, and UV-vis were applied to investigate and compare the properties of synthesized TiO2 aerogels and to determine the most effective synthesis route. The structural parameters of the synthesized materials can be varied by changing the precursor type (titanium (IV), isopropoxide (TIP), or tetrabutylorthotitanate (TBOT)) and the nature of the solvent used for additional exchange (n-hexane (nH), cyclohexane (CH), or diethyl ether (DE)). All of the subcritical dried samples show the amorphous structure, which tends to crystallize into the anatase phase after calcination. The number of micro and mesopores and the specific surface area depends on the synthesis conditions. The pores with the highest diameter have been found for additionally nH exchanged and aged aerogel synthesized from precursor TIP. Despite the imperfections in the structure, the produced aerogels show structural and optical properties typical of the TiO2 structures mentioned in the literature.

Effect of the synthesis conditions on the structural, morphological and optical properties of Bi2Te2.7Se0.3 nanoparticles

Optik ◽  
2018 ◽  
Vol 158 ◽  
pp. 199-203 ◽  
Author(s):  
H.M. Ali ◽  
E.M.M. Ibrahim ◽  
M.M. Wakkad ◽  
M.A.A. Mohamed
Keyword(s):  
Optical Properties ◽  
Synthesis Conditions
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