Structure and optical properties of nanocomposites based on polystyrene (PS) and calcium titanate (CaTiO3) perovskite nanoparticles

Optik ◽  
2021 ◽  
pp. 166963
Author(s):  
Gulstan S. Ezat ◽  
Sarkawt A. Hussen ◽  
Shujahadeen B. Aziz
Keyword(s):  
Optical Properties ◽  
Calcium Titanate ◽  
Perovskite Nanoparticles

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.

Study of structural, dielectric, optical properties and electronic structure of Cr-doped LaInO 3 perovskite nanoparticles

2017 ◽  
Vol 131 ◽  
pp. 108-115 ◽  
Author(s):  
Shiv Kumar ◽  
G.D. Dwivedi ◽  
Amish G. Joshi ◽  
Sandip Chatterjee ◽  
A.K. Ghosh
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Perovskite Nanoparticles

scholarly journals Structural and Electronic Properties of Small Perovskite Nanoparticles of the Form ABX3 (A = MA, DEA, FA, GA, B = Pb, Sn, X = Cl, Br, I)

2021 ◽  
Vol 2 (3) ◽  
pp. 382-393
Author(s):  
Christos S. Garoufalis ◽  
Iosif Galanakis ◽  
Zaiping Zeng ◽  
David B. Hayrapetyan ◽  
Sotirios Baskoutas
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
First Principles ◽  
Semiempirical Calculation ◽  
Orientational Disorder ◽  
Electronic And Optical Properties ◽  
Wide Range ◽  
Structural And Electronic Properties ◽  
Backbone Structure ◽  
Perovskite Nanoparticles

Using a combination of first principles and semiempirical calculation, we explore the structural, electronic, and optical properties of a wide range of perovskite (ABX3) nanoparticle of different size and composition. The variations of the BX3 backbone structure considered include all possible combinations of the cations B=Pb,Sn and the anions X=Cl,Br,I, while the interstitial cation A is either methylamonium (MA), or formamidinium (FA), or guanidine amine (GA), or dimethylamine (DEA). Our results indicate that the orientational disorder of the A moieties may affect the structural and electronic properties of the NPs while the optical properties exhibit a clear dependence on the NPs’ size and the types of B cations and X anions, but they are quite insensitive to the type of A cation.

Design of objective lens for 200-kV high-resolution electron microscopes

1983 ◽  
Vol 41 ◽  
pp. 314-315
Author(s):  
K. Tsuno ◽  
T. Honda ◽  
Y. Harada ◽  
M. Naruse
Keyword(s):  
Optical Properties ◽  
Computer Technology ◽  
Axial Magnetic Field ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Resolution Electron ◽  
Correction Of Astigmatism ◽  
Three Stages ◽  
Electron Microscopes ◽  
Stage 1

Developement of computer technology provides much improvements on electron microscopy, such as simulation of images, reconstruction of images and automatic controll of microscopes (auto-focussing and auto-correction of astigmatism) and design of electron microscope lenses by using a finite element method (FEM). In this investigation, procedures for simulating the optical properties of objective lenses of HREM and the characteristics of the new lens for HREM at 200 kV are described.The process for designing the objective lens is divided into three stages. Stage 1 is the process for estimating the optical properties of the lens. Firstly, calculation by FEM is made for simulating the axial magnetic field distributions Bzc of the lens. Secondly, electron ray trajectory is numerically calculated by using Bzc. And lastly, using Bzc and ray trajectory, spherical and chromatic aberration coefficients Cs and Cc are numerically calculated. Above calculations are repeated by changing the shape of lens until! to find an optimum aberration coefficients.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

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