scholarly journals Optical Characteristics of ZnCuInS/ZnS (Core/Shell) Nanocrystal Flexible Films Under X-Ray Excitation

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 343 ◽  
Author(s):  
George Saatsakis ◽  
Nektarios Kalyvas ◽  
Christos Michail ◽  
Konstantinos Ninos ◽  
Athanasios Bakas ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Light Propagation ◽  
Photon Emission ◽  
Composite Films ◽  
Optical Characteristics ◽  
Core Shell ◽  
X Ray ◽  
Optical Photon ◽  
Flexible Films ◽  
Luminescence Efficiency

The aim of this article is to evaluate optical characteristics, such as the intrinsic conversion efficiency and the inherent light propagation efficiency of three polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) composite ZnCuInS/ZnS (core/shell) nanocrystal flexible films. The concentrations of these were 100 mg/mL, 150 mg/mL, and 250 mg/mL, respectively. Composite films were prepared by homogeneously diluting dry powder quantum dot (QD) samples in toluene and subsequently mixing these with a PMMA/MMA polymer solution. The absolute luminescence efficiency (AE) of the films was measured using X-ray excitation. A theoretical model describing the optical photon propagation in scintillator materials was used to calculate the fraction of the generated optical photons passed through the different material layers. Finally, the intrinsic conversion efficiency was calculated by considering the QD quantum yield and the optical photon emission spectrum.

Characterization of Highly Luminescent LaPO4:Eu3+/LaPO4 One-Dimensional Core/Shell Heterostructures

2008 ◽  
Vol 8 (3) ◽  
pp. 1266-1271 ◽  
Author(s):  
Wenbo Bu ◽  
Jianlin Shi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Trap States ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
X Ray ◽  
Luminescence Efficiency ◽  
Transmission Electron

Highly luminescent LaPO4:Eu3+/LaPO4 one-dimensional (1D) core/shell heterostructures were successfully synthesized by a mild and simple self-aggregation process under refluxing or hydrothermal conditions. The resulting 1D core/shell heterostructures were characterized using a variety of techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray photoelectron spectroscopy (XPS) to demonstrate successful coating by the crystalline LaPO4. In addition, a possible formation mechanism for this core/shell heterostructure was proposed. Finally, the photoluminescence property of the LaPO4:Eu3+/LaPO4 1D core/shell heterostructures was investigated in detail, which illustrates that the core/shell heterostructures remarkably increase the luminescence efficiency because the LaPO4 shells effectively eliminate surface trap-states and suppress the energy quenching in the energy-transfer processes.

scholarly journals Behaviour of Y203:Eu3+ Scintillator under Radiation used in Medical Applications

2019 ◽  
Vol 7 ◽  
pp. 233
Author(s):  
I. Kandarakis ◽  
D. Cavouras ◽  
G. S. Panayiotakis ◽  
D. Koutsogiorgis ◽  
D. Triantis ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Conversion Efficiency ◽  
Light Emission ◽  
Radiation Detectors ◽  
Imaging Systems ◽  
Optical Parameters ◽  
X Ray ◽  
Luminescence Efficiency ◽  
Coating Weight ◽  
Light Conversion Efficiency

The Y2 O3:Eu3+ scintillator was studied for use in radiation detectors of medical imaging systems. Y2 O3 :Eu3+ was used in the form of laboratory prepared test screens. The x-ray luminescence efficiency of the screens was measured for tube voltages up 250 kVp. The intrinsic x-ray to light conversion efficiency (nc) and other optical parameters of the Y2 03:Eu3+ scintillator related to optical scattering, absorption, and reflection were determined. The light emission spectrum of Y2 03:Eu3+ was measured (λ=613 rim). The x-ray luminescence efficiency peaked at 180 mg/cm2 screen coating weight. The intrinsic x-ray to light conversion efficiency was found to be nc =0.095. Results indicated that Y2 03:Eu3+ is a medium to high overall performance material that could be used in medical imaging systems.

scholarly journals Chemical in‐depth analysis of (Ca/Sr)F 2 core–shell like nanoparticles by X‐ray photoelectron spectroscopy with tunable excitation energy

2021 ◽  
Vol 53 (5) ◽  
pp. 494-508
Author(s):  
Anja Müller ◽  
Thoralf Krahl ◽  
Jörg Radnik ◽  
Andreas Wagner ◽  
Carsten Kreyenschulte ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
X Ray ◽  
Depth Analysis

scholarly journals Synthesis and Advanced Characterization of Polymer-Protein Core-Shell Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 730
Author(s):  
Erik Sarnello ◽  
Tao Li
Keyword(s):  
Particle Size ◽  
Small Angle ◽  
Core Shell ◽  
Assembly Process ◽  
Shell Nanoparticles ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Core Shell Nanoparticles ◽  
Ray Scattering

Enzyme immobilization techniques are widely researched due to their wide range of applications. Polymer–protein core–shell nanoparticles (CSNPs) have emerged as a promising technique for enzyme/protein immobilization via a self-assembly process. Based on the desired application, different sizes and distribution of the polymer–protein CSNPs may be required. This work systematically studies the assembly process of poly(4-vinyl pyridine) and bovine serum albumin CSNPs. Average particle size was controlled by varying the concentrations of each reagent. Particle size and size distributions were monitored by dynamic light scattering, ultra-small-angle X-ray scattering, small-angle X-ray scattering and transmission electron microscopy. Results showed a wide range of CSNPs could be assembled ranging from an average radius as small as 52.3 nm, to particles above 1 µm by adjusting reagent concentrations. In situ X-ray scattering techniques monitored particle assembly as a function of time showing the initial particle growth followed by a decrease in particle size as they reach equilibrium. The results outline a general strategy that can be applied to other CSNP systems to better control particle size and distribution for various applications.

scholarly journals Investigation of high X-ray conversion efficiency Kr filled gas sources at the National Ignition Facility

2019 ◽  
Vol 26 (6) ◽  
pp. 063105 ◽  
Author(s):  
M. J. May ◽  
G. E. Kemp ◽  
J. D. Colvin ◽  
D. A. Liedahl ◽  
P. L. Poole ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
National Ignition Facility ◽  
X Ray

scholarly journals Magneto-Optical Characteristics of Streptavidin-Coated Fe3O4@Au Core-Shell Nanoparticles for Potential Applications on Biomedical Assays

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chin-Wei Lin ◽  
Jian-Ming Chen ◽  
You-Jun Lin ◽  
Ling-Wei Chao ◽  
Sin-Yi Wei ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Faraday Effect ◽  
Au Nanoparticles ◽  
Optical Characteristics ◽  
Enzyme Linked Immunosorbent Assay ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Time Resolved ◽  
Biotechnology Research ◽  
Core Shell Nanoparticles

Abstract Recently, gold-coated magnetic nanoparticles have drawn the interest of researchers due to their unique magneto-plasmonic characteristics. Previous research has found that the magneto-optical Faraday effect of gold-coated magnetic nanoparticles can be effectively enhanced because of the surface plasmon resonance of the gold shell. Furthermore, gold-coated magnetic nanoparticles are ideal for biomedical applications because of their high stability and biocompatibility. In this work, we synthesized Fe3O4@Au core-shell nanoparticles and coated streptavidin (STA) on the surface. Streptavidin is a protein which can selectively bind to biotin with a strong affinity. STA is widely used in biotechnology research including enzyme-linked immunosorbent assay (ELISA), time-resolved immunofluorescence (TRFIA), biosensors, and targeted pharmaceuticals. The Faraday magneto-optical characteristics of the biofunctionalized Fe3O4@Au nanoparticles were measured and studied. We showed that the streptavidin-coated Fe3O4@Au nanoparticles still possessed the enhanced magneto-optical Faraday effect. As a result, the possibility of using biofunctionalized Fe3O4@Au nanoparticles for magneto-optical biomedical assays should be explored.

scholarly journals Effect of Core-Shell Ag@TiO2Volume Ratio on Characteristics of TiO2-Based DSSCs

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ho Chang ◽  
Chih-Hao Chen ◽  
Mu-Jung Kao ◽  
Hsin-Han Hsiao
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Core Shell ◽  
Photoelectric Conversion ◽  
Shell Type ◽  
Degussa P25 ◽  
Triton X

This paper aims to develop photoanode material required by dye-sensitized solar cells. The material prepared is in the form of Ag@TiO2core-shell-type nanocomposites. This material is used to replace the titanium oxide powder commonly used in general DSSCs. The prepared Ag@TiO2core-shell-type nanocomposites are mixed with Degussa P25 TiO2in different proportions. Triton X-100 is added and polyethylene glycol (PEG) at 20 wt% is used as a polymer additive. This study tests the particle size and material properties of Ag@TiO2core-shell-type nanocomposites and measures the photoelectric conversion efficiency and IPCE of DSSCs. Experimental results show that the DSSC prepared by Ag@TiO2core-shell-type nanocomposites can achieve a photoelectric conversion efficiency of 3.67%. When Ag@TiO2core-shell-type nanocomposites are mixed with P25 nanoparticles in specific proportions, and when the thickness of the photoelectrode thin film is 28 μm, the photoelectric conversion efficiency can reach 6.06%, with a fill factor of 0.52, open-circuit voltage of 0.64V, and short-circuit density of 18.22 mAcm−2. Compared to the DSSC prepared by P25 TiO2only, the photoelectric conversion efficiency can be raised by 38% under the proposed approach.

scholarly journals Core-shell and gradient morphology polymer particles analyzed by X-ray photoelectron spectroscopy: Effect of monomer feed order

2017 ◽  
Vol 55 (15) ◽  
pp. 2513-2526 ◽  
Author(s):  
Florent Jasinski ◽  
Victoria L. Teo ◽  
Rhiannon P. Kuchel ◽  
Monique Mballa Mballa ◽  
Stuart C. Thickett ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Polymer Particles ◽  
X Ray ◽  
Monomer Feed

Luminescence efficiency of Gd/sub 2/SiO/sub 5/:Ce scintillator under X-ray excitation

2005 ◽  
Vol 52 (5) ◽  
pp. 1830-1835 ◽  
Author(s):  
I.G. Valais ◽  
I.S. Kandarakis ◽  
D.N. Nikolopoulos ◽  
I.A. Sianoudis ◽  
N. Dimitropoulos ◽  
...  
Keyword(s):  
X Ray ◽  
Luminescence Efficiency
Sign in / Sign up

Export Citation Format

Share Document