Effect of Co-Doping on the Photoluminescent Behavior and Electronic Structure of Zinc Silicate Phosphors

1999 ◽  
Vol 560 ◽  
Author(s):  
H.D. Park ◽  
K.-S. Sohn ◽  
B. Cho ◽  
H. Chang
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
First Principles ◽  
Zinc Silicate ◽  
Co Doping ◽  
Silicate Phosphors

ABSTRACTThe present study aims at investigating the effect of co-doping on the photoluminescence(PL) property of Zn2SiO4:Mn phosphor. Experimental data were interpreted by the first principles embedded-cluster discrete variational (DV)-Xα method.

Effects of co-doping on electronic structure and optical properties of 3C-SiC from first-principles method

2019 ◽  
Vol 170 ◽  
pp. 109172 ◽  
Author(s):  
Xuefeng Lu ◽  
Tingting Zhao ◽  
Qingfeng Lei ◽  
Xiaobin Yan ◽  
Junqiang Ren ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Co Doping ◽  
First Principles Method

Impact of Dopants on the PbTe Thermoelectric Efficiency

2010 ◽  
Vol 1267 ◽  
Author(s):  
Ka Xiong ◽  
Rahul P Gupta ◽  
John B White ◽  
Bruce Gnade ◽  
Kyeongjae Cho
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
Charge State ◽  
First Principles ◽  
First Principles Calculations ◽  
Defect Level ◽  
Thermoelectric Efficiency ◽  
Group Iii ◽  
The Impact

AbstractWe investigated the impact of doping group III elements (Al, Ga, In and Tl) on the electronic structure of PbTe by first principles calculations. The impurity-induced defect level changes with respect to the charge state of the impurity. We find that among the four elements, Tl is the best candidate for the enhancement of thermoelectric efficiency, consistent with the experimental data.

Electronic and optical properties of CeO2 from first principles calculations

2016 ◽  
Vol 8 (25) ◽  
pp. 5045-5052 ◽  
Author(s):  
Mohammed El Khalifi ◽  
Fabien Picaud ◽  
Mohamed Bizi
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic And Optical Properties

First principles calculations of the electronic structure of CeO2 nanoparticles (NPs) were performed to investigate published experimental data obtained by different spectroscopies.

scholarly journals Brief history of computational chemistry: Three distinct eras and the relative importance of theoretical insights and computing power in advancing the field

2014 ◽  
Author(s):  
Wenfa Ng
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
Schrödinger Equation ◽  
Computational Chemistry ◽  
First Principles ◽  
Schrodinger Equation ◽  
Computational Time ◽  
Computational Power ◽  
Computing Power ◽  
Simplifying Assumptions

The past influences the present and future; for example, in computational chemistry, simplifying assumptions and approximations critical to problem-solving in the pre-computing era remains relevant today in allowing simulation of larger systems with reasonable amount of computational time. By highlighting significant milestones in efforts - from both theoretical and simulation perspectives - aimed at understanding the nature of chemical bond formation, this abstract-only preprint describes a short essay that traces the development and evolution of electronic structure calculation methods over the years, as well as demystify many of the field’s technical terms (jargons) and eponymous method names that has presented a significant entry barrier to newcomers. Schrodinger equation occupies central place in computational chemistry, where the focus was, and will continue to be, the development of methods for its solution. Placing the various methods along a time-line and observing the temporal relationships between them, reveals the clustering of methods into three distinct eras, each defined by their relative reliance on theory, approximations, experimental data and computational power for problem solution. Specifically, building of theoretical models for explaining spectroscopic emission spectra laid the initial foundation of the field when theory lagged behind experimental observations. Promulgation of the Schrodinger equation – which describes total system energy and properties via a quantum mechanical framework - shifted the research focus of the field towards its solution. Nevertheless, difficulty in solving the equation during the pre-computing era spawned an entire sub-field seeking to develop increasingly refined methods for obtaining approximate solutions. Specifically, semi-empirical methods rely on experimental data to supply parameter values inaccessible via direct calculations from first principles, while approximate methods use simplifications, for example, to obviate the need for calculating cross-interacting terms. Availability of large amount of inexpensive computational power in recent years, however, brought forth ab initio (first principles) simulation methods capable of calculating electronic structure properties of large systems (e.g., long chain biomolecules) with few or no simplifying assumptions. Finally, the chronological thread delineated also provides the backdrop for asking counterfactual (“what if”) questions examining, from a historical vantage point, the relative roles of computational power and theoretical intuition in the development of computational chemistry. Contrary to widespread notions that advances in computational chemistry are solely potentiated by increases in computing power, the article argues – via examples - that the relationship between theoretical imagination and computing power is more nuanced: specifically, the two alternately exert their influence at different junctures during the field’s evolution.

Electronic Structure of Planar Faults and Point Defects in High Temperature Intermetallics

1991 ◽  
Vol 253 ◽  
Author(s):  
J.M. Maclaren ◽  
C. Woodward
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
High Temperature ◽  
Point Defects ◽  
First Principles ◽  
Electronic Structure Calculations ◽  
Recent Experimental Data ◽  
Structure Calculations

ABSTRACTFirst principles electronic structure calculations, using the layer Korringa-Kohn-Rostoker method, are reported for isolated planar faults in TiAl. The calculated fault energies are discussed in the context of suggested superdislocation separation reactions. The influence of dilute impurities on fault energies are treated using the coherent potentialapproximation. Using this approach, the variation of fault energies in TiAl resulting from stoichiometry changes and from the addition of Mn axe calculated, and compared to recent experimental data.

scholarly journals First-principles Calculation of the Electronic Structure and Optical Properties of ZnO Co-doped with Nb and Ta

2019 ◽  
Vol 25 (3) ◽  
pp. 238-245 ◽  
Author(s):  
Jinpeng WANG ◽  
Tao SHEN ◽  
Hongchen LIU
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculation ◽  
Ultraviolet Region ◽  
First Principle ◽  
Co Doping ◽  
First Principle Calculations ◽  
Function Loss ◽  
Co Doped

First-principle calculations have been performed to investigate the electronic structure and optical properties of ZnO co-doped with Nb and Ta. The three doping structures are set to: Zn0.9375Nb0.0625O, Zn0.9375Ta0.0625O and Zn0.875Nb0.0625Ta0.0625O. The experiments show that co-doping with Nb and Ta narrows the band gap. And it causes the Fermi level to shift upwards and enter the conduction band, while enhancing the conductivity of the doped system. In addition, it has been determined that the dielectric imaginary part of the dopant system is larger than that of the pure ZnO in the low energy region. The absorption side of the dopant system, on the other hand, exhibits a redshift. Furthermore, the transmittance of the ultraviolet region is significantly increased, and the function loss spectrum appears to redshift. This will provide a good theoretical basis for the study and the applications of photoelectric materials co-doped with Nb and Ta. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19956

First-principles study of the electronic structure of Al and Sn co-doping ZnO system

2013 ◽  
Vol 16 (4) ◽  
pp. 1057-1062 ◽  
Author(s):  
Xiurong Qu ◽  
Shuchen Lü ◽  
Dechang Jia ◽  
Sheng Zhou ◽  
Qingyu Meng
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Co Doping ◽  
First Principles Study
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