Photoluminescence Kinetics Model of P-Type GaAs:Nd

1996 ◽  
Vol 422 ◽  
Author(s):  
U. K. Saha ◽  
H. J. Lozykowski
Keyword(s):  
Experimental Data ◽  
Energy Transfer ◽  
Rare Earth ◽  
Excitation Power ◽  
Host Lattice ◽  
The Core ◽  
Type Semiconductor ◽  
P Type ◽  
Kinetics Of ◽  
Good Agreement

AbstractIn this work we have developed a model for the kinetics of the energy transfer from the host lattice to the core states of rare earth (RE) centers. We have derived a set of kinetics differential equations of RE luminescence in p-type semiconductor. Numerically computed rise and decay time of RE luminescence as a function of excitation power shows good agreement with the experimental data obtained for p-type GaAs:Nd.

Kinetics of the Luminescence of Isoelectronic Rare-Earth Ions In III-V Semiconductors

1993 ◽  
Vol 301 ◽  
Author(s):  
H.J. Lozykowski
Keyword(s):  
Experimental Data ◽  
Energy Transfer ◽  
Rare Earth ◽  
Excited States ◽  
Quantitative Agreement ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Wide Range ◽  
Decay Times ◽  
Kinetics Of

ABSTRACTIn this work we have developed a model for the kinetics of the energy transfer from the host lattice to the localized core excited states of rare earth isoelectronic structured traps (REI-trap). We have derive a set of differential equations for semi-insulating semiconductor governing the kinetics of rare earth luminescence. The numerically simulated rise and decay times of luminescence show a good quantitative agreement with the experimental data obtained for InP:Yb, over a wide range of generation rates.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

Prediction of Cavitation Inception Within Regions of Flow Separation

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Flow Separation ◽  
Computational Method ◽  
Average Flow ◽  
Cavitation Inception ◽  
The Core ◽  
Good Agreement

Cavitation within regions of flow separation appears in drifting vortices. A two-part computational method is employed for prediction of cavitation inception number there. The first part is an analysis of the average flow in separation regions without consideration of an impact of vortices. The second part is an analysis of equilibrium of the bubble within the core of a vortex located in the turbulent flow of known average characteristics. Computed cavitation inception numbers for axisymmetric flows are in the good agreement with the known experimental data.

scholarly journals Кинетика нарастания ап-конверсионной люминесценции кристалла LiY-=SUB=-0.8-=/SUB=-Yb-=SUB=-0.2-=/SUB=-F-=SUB=-4-=/SUB=- : Tm-=SUP=-3+-=/SUP=- (0.2 at.%) при импульсном возбуждении

2019 ◽  
Vol 61 (5) ◽  
pp. 953
Author(s):  
А.В. Михеев ◽  
Б.Н. Казаков
Keyword(s):  
Regression Analysis ◽  
Energy Transfer ◽  
Rare Earth ◽  
Laser Diode ◽  
Rare Earth Ions ◽  
Experimental Conditions ◽  
Pulsed Excitation ◽  
Transfer Processes ◽  
Dipole Interactions ◽  
Kinetics Of

AbstractThe regression analysis of the rise kinetics of up-conversion luminescence of the LiY_0.8Yb_0.2F_4:Tm^3+ (0.2 at %) crystal is performed. The kinetics curve is obtained with rectangular pulsed excitation by radiation from a laser diode (IR LD) with a wavelength of λ_ p = 933 nm. The most important—in these experimental conditions—mechanisms of the energy transfer from Yb^3+ ions to Tm^3+ ions are established, which are responsible for the transitions between the ground ^3 H _6 and excited ^3 F _4, ^3 H _4, ^1 G _4, ^1 D _2, and ^1 I _6 terms of the Tm^3+ ions. The durations of the relevant energy transfer processes are determined. It is shown that the energy transfer between rare earth ions in the LiY_0.8Yb_0.2F_4:Tm^3+ (0.2 at %) crystal occurs through the dipole–dipole interactions.

scholarly journals Modelling the Characteristics of Ring-Shaped Magnetoelastic Force Sensor in Mohri’s Configuration

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 266 ◽  
Author(s):  
Anna Ostaszewska-Liżewska ◽  
Roman Szewczyk ◽  
Peter Raback ◽  
Mika Malinen
Keyword(s):  
Experimental Data ◽  
High Sensitivity ◽  
Force Sensor ◽  
Inhomogeneous Distribution ◽  
The Finite Element Method ◽  
The Core ◽  
Magnetoelastic Effect ◽  
Proposed Model ◽  
Distribution Of Stresses ◽  
Good Agreement

Magnetoelastic force sensors exhibit high sensitivity and robustness. One commonly used configuration of force sensor with a ring-shaped core was presented by Mohri at al. In this configuration force is applied in the direction of a diameter of the core. However, due to inhomogeneous distribution of stresses, model of such sensor has not been presented yet. This paper is filling the gap presenting a new method of modelling the magnetoelastic effect, which is especially suitable for the finite element method. The presented implementation of proposed model is in good agreement with experimental data and creates new possibilities of modelling other devices utilizing magnetoelastic effect.

Post-Test Investigations of BFBT Critical Power Tests With Trace

2009 ◽  
Author(s):  
Marc Thieme ◽  
Wolfgang Tietsch ◽  
Rafael Macian ◽  
Victor Hugo Sanchez Espinoza
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Critical Power ◽  
The Core ◽  
Fine Mesh ◽  
The Us ◽  
Post Test ◽  
Trace Model ◽  
Good Agreement ◽  
Transfer Models

The validation of heat transfer models of safety analysis codes such as TRACE is very important due to the strong interaction of the thermal hydraulics parameters with the core neutronics. TRACE is the reference system code of the US NRC for LWR. It is being developed and extensively validated within the international CAMP-program. In this paper, the validation of heat transfer models of TRACE related to the prediction of the critical power is presented. The validation is based on a large number of critical power tests performed in the NUPEC BFBT (BWR Full-Size Fine-Mesh Bundle Tests) facility in Japan. These tests were analysed with the TRACE Version 5 RC 2. The comparison of predictions with the experimental data shows good agreement. The developed TRACE model and the comparison of experimental data with code results will be presented and discussed.

Kathodolumineszenz der Seltenerd-aktivierten Wirtsgitter Sr3La2W2O12 und Ca2La0,5Na0,5WO6

1985 ◽  
Vol 40 (5) ◽  
pp. 503-507 ◽  
Author(s):  
R. Braun ◽  
R. Otto ◽  
W. Wischert ◽  
S. Kemmler-Sack
Keyword(s):  
Electronic Structure ◽  
Energy Transfer ◽  
Rare Earth ◽  
Visible Region ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Emission Efficiency ◽  
Transfer Processes ◽  
Trivalent Rare Earth ◽  
Host Lattices

By activation of the host lattices Sr3La2W2O12 and Ca2La0,5Na0,5WO6 with the trivalent rare earth ions Ln3+ = Pr, Sm, Eu, Tb, Dy, Ho, Er a cathodoluminescence in the visible region is obtained. The influence of the electronic structure and concentration of the activator on the relative emission efficiency as well as the host lattice participation in the energy transfer processes are discussed.

scholarly journals First-Principles Calculations of the Structural, Electronic and Optical Properties of Yttrium-Doped SnO2

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nabil Beloufa ◽  
Youcef Chechab ◽  
Souad Louhibi-Fasla ◽  
Abbes Chahed ◽  
Samir Bekheira ◽  
...  
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Level Shifts ◽  
Type Semiconductor ◽  
Direct Band ◽  
P Type ◽  
Theoretical Results ◽  
Good Agreement

Abstract We use FP-LAPW method to study structural, electronic, and optical properties of the pure and Y-doped SnO2. The results show that by Y doping of SnO2 the band gaps are broadened, and still direct at Γ-point. For pure SnO2 material, the obtained values of the direct band gap are 0.607 eV for GGA-PBE and 2.524 eV for GGATB-mBJ, respectively. This later is in good agreement with the experimental data and other theoretical results. The Fermi level shifts into the valence band and exhibits p-type semiconductor character owing mainly from the orbital 4d-Y. Additionally, the calculated optical properties reveal that all concentrations are characterized by low reflectivity and absorption via wavelength λ (nm) in the visible light and near-infrared (NIR) ranges, which leads to a redshift in the optical transparency.

Magnetic Properties of PrхY1-xFe3(BO3)4

2015 ◽  
Vol 233-234 ◽  
pp. 360-363
Author(s):  
A.I. Pankrats ◽  
A.A. Demidov ◽  
D.A. Velikanov ◽  
V.I. Tugarinov ◽  
V.L. Temerov
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Magnetic Properties ◽  
Rare Earth ◽  
Field Model ◽  
Field Approximation ◽  
Magnetization Curves ◽  
Extensive Experimental Data ◽  
Theory And Experiment ◽  
Good Agreement

The magnetic properties of trigonal PrxY1-xFe3(BO3)4 compound have been investigated. Anomalies on the magnetization curves induced by a magnetic field are observed for each composition. The calculations were performed using a molecular-field approximation and a crystal-field model for the rare-earth subsystem. Extensive experimental data on the magnetic properties of PrxY1-xFe3(BO3)4 have been interpreted and good agreement between theory and experiment has been achieved.

Photolumineszenz und Energietransfer in Seltenerd-aktivierten Granat Gd3Te2Li3O12 / Photolwninescence and Energy Transfer in the Rare Earth Activated Garnet Gd3Te2Li3O12

1984 ◽  
Vol 39 (5) ◽  
pp. 490-494 ◽  
Author(s):  
B. Köngeter ◽  
S. Kemmler-Sack
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Visible Emission ◽  
Luminescence Properties ◽  
Trivalent Rare Earth ◽  
The Rare Earth

By activation of the cubic garnet host lattice Gd3Te2Li3O12 with trivalent rare earth ions the most intense visible emission is observed for Ln3+ = Eu, Tb. Energy transfer from Gd3+ to Sm3+, Eu3+ or Dy3+, from Tb3+ to Eu3+ and from Er3+ to Tm3+ has been found to occur. The luminescence properties are strongly influenced by the substitution of Te6+ by W6+ (systems Gd3-xLnxTe2-yWyLi3O12)

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