scholarly journals Experimental Study of Optical Properties of Polymeric Nanowires

2020 ◽  
Author(s):  
Mohamed Mbarek ◽  
Abeer Altowyan ◽  
Nawal Almaymoni
Keyword(s):  
Experimental Study ◽  
Optical Properties ◽  
Energy Transfer ◽  
Diffusion Length ◽  
Energy Transfer Process ◽  
Life Time ◽  
Average Life ◽  
The Core ◽  
Förster Energy Transfer ◽  
Experimental Decay

Abstract Photo-emissive properties including steady-state and transient photoluminescence (PL) spectroscopy are studied for blinding and coaxial nanowires based PPV and PVK. PL data or average life time of excitons depending exclusively of the nanostructures architecture. Furthermore, the interpretation of PL spectra requires invoking the migration and the diffusion length of photo-generated exciton from luminophores to other luminophores or from the core to the shell. This process is able to explain the experimental decay of PL in the nano-second time scale. The evidence of Forster energy transfer (FET) and charge transfer (CT) has been investigated in the synthesis nanostructures. An enhancement and amplification PPV luminophore emission by the presence of PVK luminophore in blinding or coaxial nanowires due to energy transfer process.

Luminescence Properties of Ytterbium and Oxygen Coimplanted InP

1995 ◽  
Vol 417 ◽  
Author(s):  
H. J. Lozykowski ◽  
A. K. Alshawa
Keyword(s):  
Energy Transfer ◽  
Annealing Temperature ◽  
Energy Transfer Process ◽  
Deep Trap ◽  
The Core ◽  
Sufficient Energy ◽  
Intrinsic Excitation ◽  
Direct Energy ◽  
Deep Donor ◽  
Effect Of Oxygen

AbstractIn this work we report a systematic study of the effect of oxygen on ytterbium 4f- 4f emission by coimplanting Yb and O into InP. The PL spectra of InP: Yb and InP: (Yb+O) as a function of annealing temperature and duration were studied. In addition the photoluminescence and kinetic processes were investigated as a function of temperature and excitation intensity.The investigation shows that the codoped oxygen reduces drastically the Yb3+ emissioon from SI and n-type InP:Yb under intrinsic excitation. The codoping of Yb and 0 may create a complex involving a YbIn and Op. This structured isoelectronic (YbIn- Op) complex, may behave as a deep trap (or a deep donor) located approximately at the middle of bandgap. Exciton bound to such centers will not have sufficient energy to excite the core Yb 4f electrons by Auger direct energy transfer process.

scholarly journals Ферстеровский резонансный перенос энергии с участием светлых и темных экситонов в массивах эпитаксиальных квантовых точек CdSe/ZnSe

2018 ◽  
Vol 60 (8) ◽  
pp. 1575
Author(s):  
Т.Н. Михайлов ◽  
Е.А. Европейцев ◽  
К.Г. Беляев ◽  
A.A. Торопов ◽  
A.В. Родина ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Energy Transfer Process ◽  
Dipole Interaction ◽  
Energy Transfer Mechanism ◽  
Time Resolved ◽  
Decay Times ◽  
Förster Energy Transfer ◽  
Excitonic States ◽  
Time Resolved Photoluminescence

AbstractUsing time-resolved photoluminescence (PL) spectroscopy, we establish the presence of the Förster energy transfer mechanism between two arrays of epitaxial CdSe/ZnSe quantum dots (QDs) of different sizes. The mechanism operates through dipole–dipole interaction between ground excitonic states of the smaller QDs and excited states of the larger QDs. The dependence of energy transfer efficiency on the width of barrier separating the QD insets is shown to be in line with the Förster mechanism. The temperature dependence of the PL decay times and PL intensity suggests the involvement of dark excitons in the energy transfer process.

scholarly journals Enhanced Energy-Transfer Properties in Core-Shell Photoluminescent Nanoparticles Using Mesoporous SiO2 Intermediate Layers

2020 ◽  
Vol 58 (2) ◽  
pp. 137-144
Author(s):  
Woo Hyeong Sim ◽  
Seyun Kim ◽  
Weon Ho Shin ◽  
Hyung Mo Jeong
Keyword(s):  
Optical Properties ◽  
Energy Transfer ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Infrared Light ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Intermediate Layers ◽  
Core Shell Nanoparticles

Multi-layer core-shell nanoparticles (YVO<sub>4</sub>:Nd<sup>3+</sup>/mSiO<sub>2</sub>/SiO<sub>2</sub>) consisting of silica cores (SiO<sub>2</sub>), mesoporous silica (mSiO<sub>2</sub>) intermediate layers, and Neodymium doped rare-earth phosphor (YVO<sub>4</sub>:Nd<sup>3+</sup>) shell layers were successfully synthesized using the stepwise sol-gel method. The morphological structure and optical properties of the functional core-shell nanoparticles were characterized and evaluated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) analysis. mSiO<sub>2</sub> intermediate layers were utilized as the bridge between the core and shell materials. Their porous surfaces served to anchor the YVO<sub>4</sub>:Nd<sup>3+</sup> crystals. This prevents energy loss during the energy transfer of electrons, resulting in improved optical properties. The use of intermediate layer combinations of mSiO<sub>2</sub>/SiO<sub>2</sub> in the coreshell structure also improved cost-effectiveness, because the core is filled with cheap silica, not expensive phosphors. Even though the nanoparticles used only a thin layer of the photoluminescent shell materials, the optical properties, resulting from the energy-transfer emitting mid-infrared light, were remarkably enhanced by increasing the crystallinity of the phosphor. To demonstrate the practical use of the synthesis method, the photoluminescent properties of the core-shell nanoparticles were optimized by adjusting the annealing temperature and scaling to mass production. We believe that our efficient synthetic strategy provides a facile way of obtaining functional, cost-effective core-shell nanoparticles with improved photoluminescent properties.

Heat, quantum mechanics and information

2015 ◽  
Vol 10 (2) ◽  
pp. 2692-2695
Author(s):  
Bhekuzulu Khumalo
Keyword(s):  
Information Theory ◽  
Quantum Mechanics ◽  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Process Information ◽  
Double Slit Experiment ◽  
Slit Experiment ◽  
Double Slit

Heat has often been described as part of the energy transfer process. Information theory says everything is information. If everything is information then what type of information is heat, this question can be settled by the double slit experiment, but we must know what we are looking for. 

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