Theoretical Study of the Electronic Structures of Li-Doped ZnO

2012 ◽  
Vol 535-537 ◽  
pp. 214-218
Author(s):  
Qi Xin Wan ◽  
Jia Yi Chen ◽  
Zhi Hua Xiong ◽  
Dong Mei Li ◽  
Bi Lin Shao ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Formation Energy ◽  
Lattice Distortion ◽  
Theoretical Study ◽  
Functional Theory ◽  
Li Doping ◽  
The Density Functional Theory ◽  
Doped Zno ◽  
Good Agreement

The first-principles with pseudopotentials method based on the density functional theory was applied to calculate the geometric structure, the formation energy of impurities and the electronic structure of Li-doped ZnO. In the system of Li-doped ZnO, LiZn can not result in lattice distortion. In contrast with that case, LiO and Lii result in lattice distortion after Li doping in ZnO. In Li-doped ZnO, LiO is the most unstable than the other cases. Simultaneously, Lii is more stable than LiZn according to that Lii has smaller formation energy. Furthermore, the electronic structure of Li-doped ZnO indicates that that LiZn behaves as acceptor, while Lii behaves as donor. In conclusion, in Li-doped ZnO, Lii is always in the system to compensate the acceptor. Singly doping Li in ZnO is difficult to gain p-ZnO for the self-compensation. The results are in good agreement with other calculated and experimental results.

Theoretical Study of the Electronic Structures of Na-Doped ZnO

2014 ◽  
Vol 665 ◽  
pp. 124-127 ◽  
Author(s):  
Qi Xin Wan ◽  
Bi Lin Shao ◽  
Zhi Hua Xiong ◽  
Dong Mei Li ◽  
Guo Dong Liu
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Formation Energy ◽  
Theoretical Study ◽  
The Other ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Doped Zno

The first-principles with pseudopotentials method based on the density functional theory was applied to calculate the formation energy of impurities and the electronic structure of ZnO doped with Na. In Na-doped ZnO, NaOis the most unstable than the other cases. Simultaneously, NaZnis more stable than Naiaccording to that NaZnhave smaller formation energy. Furthermore, the electronic structure of Na-doped ZnO indicates that that NaZnbehaves as an acceptor, while Naibehaves as a donor.

scholarly journals An efficient synthesis of novel triazoles incorporating barbituric motifs via [3+2] cycloaddition reaction: An experimental and theoretical study

2018 ◽  
Vol 83 (7-8) ◽  
pp. 821-835 ◽  
Author(s):  
Mahdieh Darroudi ◽  
Yaghoub Sarrafi ◽  
Mahshid Hamzehloueian
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Cycloaddition Reaction ◽  
Frontier Molecular Orbital ◽  
Knoevenagel Reaction ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Copper Acetylide ◽  
Good Agreement ◽  
Uncatalysed Reaction

In this work, the synthesis of novel triazole derivatives with barbituric motifs in good yields is described. The alkyne was prepared through the Knoevenagel reaction of barbituric derivatives with ortho and para O-propargylated hydroxybenzaldehyde. The mechanism and regioselectivity of this [3+2] cycloaddition reaction were investigated using the density functional theory at the B3LYP/6-31+G(d) level of theory. The computational studies revealed that a di-copper catalyzed stepwise mechanism, involving six-membered ring intermediate, is the preferred pathway. The regioselectivity was explained in terms of frontier molecular orbital (FMO) interactions, local and global electrophilicity and nucleophilicity indices. Accordingly, the favored interactions for di-copper acetylide are in good agreement with the observed regioselectivity, while completely opposite results were obtained for a possible uncatalysed reaction.

Theoretical Studies on P-Type Conduction in (S,Cu) Co-Doped ZnO

2011 ◽  
Vol 306-307 ◽  
pp. 269-273 ◽  
Author(s):  
Zhi Hua Xiong ◽  
Lan Li Chen ◽  
Chang Da Zheng
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Formation Energy ◽  
Functional Theory ◽  
Rich Condition ◽  
Acceptor Energy Level ◽  
Doped Zno ◽  
Complex Forms ◽  
P Type ◽  
Co Doped

Based on the first-principles calculations with density functional theory, the formation energy and electronic structure of (S, Cu) co-doped ZnO has been investigated, where the doping cases including related defects for Cu mono-doped, S-Cu co-doped, and S-2Cu co-doped ZnO are studied. The calculated results show that the formation energy of S-2Cu complex is lower than that of S-Cu complex under the O-rich condition. From the electronic structure, S-2Cu complex forms a peak of impurity state at the top of valence band. It was further found that heavy doping of Cu, not only enhances the acceptor concentration, but also leads to shallower acceptor energy level. Therefore, we concluded that S-2Cu complex is suitable for yielding better p-type conductivity in ZnO. The results are in good agreement with the experiment results.

Structure, stability and intramolecular interaction of M(N5)2(M = Mg, Ca, Sr and Ba) : a theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21823-21830 ◽  
Author(s):  
Xueli Zhang ◽  
Junqing Yang ◽  
Ming Lu ◽  
Xuedong Gong
Keyword(s):  
Energetic Materials ◽  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Intramolecular Interaction ◽  
Earth Metal ◽  
Structure Stability ◽  
Alkaline Earth Metal ◽  
Functional Theory ◽  
The Density Functional Theory

The potential energetic materials, alkaline earth metal complexes of the pentazole anion (M(N5)2, M = Mg2+, Ca2+, Sr2+and Ba2+), were studied using the density functional theory.

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.

scholarly journals Oxygen vacancy and doping atom effect on electronic structure and optical properties of Cd2SnO4

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 640-646 ◽  
Author(s):  
Mei Tang ◽  
JiaXiang Shang ◽  
Yue Zhang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
La Doped ◽  
Doping Atom ◽  
Atom Effect

The electronic structure and optical properties of oxygen vacancy and La-doped Cd2SnO4 were calculated using the plane-wave-based pseudopotential method based on the density functional theory (DFT) within the generalized gradient approximation (GGA).

scholarly journals Effect of Yb Concentration on the Structural, Magnetic and Optoelectronic Properties of Yb Doped ZnO: First Principles Calculation

2021 ◽  
Author(s):  
Mohamed Achehboune ◽  
Mohammed Khenfouch ◽  
Issam Boukhoubza ◽  
Issam Derkaoui ◽  
Bakang Moses Mothudi ◽  
...  
Keyword(s):  
Band Gap ◽  
Conduction Band ◽  
Density Functional ◽  
Blue Shift ◽  
First Principles Calculation ◽  
Theoretical Research ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Doped Zno ◽  
Good Agreement

Abstract Density functional theory-based investigation of the electronic, magnetic, and optical characteristics in pure and ytterbium (Yb) doped ZnO has been carried out by the plane-wave pseudopotential technique with generalized gradient approximation. The calculated lattice parameters and band gap of pure ZnO are in good agreement with the experimental results. The energy band-gap increases with the increase of Yb concentration. The Fermi level moves upward into the conduction band after doping with Yb, which shows the properties of an n-type se miconductor. New defects were created in the band-gap near the conduction band attributed to the Yb-4f states. The magnetic properties of ZnO were found to be affected by Yb doping; ferromagnetic property was observed for 4.17% Yb due to spin polarization of Yb-4f electrons. The calculated optical properties imply that Yb doped causes a blue shift of the absorption peaks, significantly enhances the absorption of the visible light, and the blue shift of the reflectivity spectrum was observed. Besides, a better transmittance of approximately 88% was observed for 4.17% Yb doped ZnO system. The refractive index and the extinction coefficient were observed to decrease as the Yb dopant concentration increased. As a result, we believe that our findings will be useful in understanding the doping impact in ZnO and will motivate further theoretical research.

scholarly journals A look at the density functional theory zoo with the advanced GMTKN55 database for general main group thermochemistry, kinetics and noncovalent interactions

2017 ◽  
Vol 19 (48) ◽  
pp. 32184-32215 ◽  
Author(s):  
Lars Goerigk ◽  
Andreas Hansen ◽  
Christoph Bauer ◽  
Stephan Ehrlich ◽  
Asim Najibi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Noncovalent Interactions ◽  
Main Group ◽  
Density Functionals ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Benchmark Database ◽  
Electronic Structure Methods

We present the updated and extended GMTKN55 benchmark database for more accurate and extensive energetic evaluation of density functionals and other electronic structure methods with detailed guidelines for method users.

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