Electronic Structure of O-vacancy in High-k Dielectrics and Oxide Semiconductors

2011 ◽  
Vol 1370 ◽  
Author(s):  
Kee Joo Chang ◽  
Byungki Ryu ◽  
Hyeon-Kyun Noh ◽  
Junhyeok Bang ◽  
Eun-Ae Choi
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Device Performance ◽  
Oxide Semiconductors ◽  
Vacancy Defects ◽  
High K ◽  
Quasiparticle Energy ◽  
O Vacancy ◽  
Hybrid Density Functional

ABSTRACTFirst-principles density functional calculations are performed to investigate the electronic properties of O-vacancy defects in high-k HfO2, Si/HfO2 interface, and amorphous oxide semiconductors. The role of O-vacancy in device performance is discussed by comparing the results of the GGA, hybrid density functional, and quasiparticle energy calculations.

Exploring the role of vacancy defects in the optical properties of LiMgPO4

2020 ◽  
Vol 22 (28) ◽  
pp. 16244-16257 ◽  
Author(s):  
Pampa Modak ◽  
Brindaban Modak
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Structure Calculation ◽  
Hybrid Density Functional Theory ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Hybrid Density Functional

A systematic electronic structure calculation employing hybrid density functional theory has been carried out to explore the role of all possible vacancy defects in neutral and charged states in the optical properties of LiMgPO4.

scholarly journals The role of intrinsic vacancy defects in the electronic and magnetic properties of Sr3SnO: a first-principles study

RSC Advances ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 6880-6888 ◽  
Author(s):  
Javaria Batool ◽  
Syed Muhammad Alay-e-Abbas ◽  
Adnan Ali ◽  
Khalid Mahmood ◽  
Shaheen Akhtar ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Stability Diagram ◽  
Vacancy Defects ◽  
Electronic And Magnetic Properties ◽  
O Vacancy ◽  
Formation Energies ◽  
Thermodynamic Stability Diagram

The thermodynamic stability diagram and formation energies of intrinsic vacancy defects in Sr3SnO. Sr and O vacancy containing Sr3SnO is non-magnetic, while ferromagnetism is achieved in Sn deficient Sr3SnO.

Pros and cons of time-dependent hybrid density functional approach to optical spectra of solids: a case study of CeO2

2021 ◽  
Author(s):  
Huai-Yang Sun ◽  
Shuo-Xue Li ◽  
Hong Jiang
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Computational Cost ◽  
Optical Spectra ◽  
First Principles Calculation ◽  
Many Body ◽  
Many Body Perturbation Theory ◽  
Pros And Cons ◽  
Hybrid Density Functional

Prediction of optical spectra of complex solids remains a great challenge for first-principles calculation due to the huge computational cost of the state-of-the-art many-body perturbation theory based GW-Bethe Salpeter equation...

Preliminary First Principles Study Of Hf and Zr Aluminates as Replacement High-k Dielectrics

2001 ◽  
Vol 670 ◽  
Author(s):  
Michael Haverty ◽  
Atsushi Kawamoto ◽  
Gyuchang Jun ◽  
Kyeongjae Cho ◽  
Robert Dutton
Keyword(s):  
Density Functional Theory ◽  
Dielectric Constant ◽  
Bulk Density ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Conduction Band Edge ◽  
Functional Theory ◽  
Trade Off ◽  
High K

ABSTRACTBulk Density Functional Theory calculations were performed on Hf and Zr substitutions for Al in κ-alumina. The lowest energy configuration found was an octahedrally coordinated Zr site. Zr dissolution was favorable with an enthalpy of -2eV/unit cell for forming Al1.875Zr0.125O3 from pure Zr and κ-alumina. Hf and Zr substitution for Al atoms introduced empty d-states below the conduction band edge reducing the Eg of pure κ-alumina (7.5eV) to 6.4-5.9eV. The edge of the valence band however remained fixed by the O p-state character. The substitution of Hf and Zr into the alumina structure may lead to a higher dielectric constant, but will also reduce Eg and result in a trade off in tunneling currents in devices.

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

Electronic Structure and Hydrogen Desorption in NaAlH4

2004 ◽  
Vol 837 ◽  
Author(s):  
S. Li ◽  
P. Jena ◽  
C. M. Araujo ◽  
R. Ahuja
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Metal Hydrides ◽  
Hydrogen Desorption ◽  
Light Metal ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Design And Synthesis

ABSTRACTFirst principles calculations based on gradient corrected density functional theory are carried out to understand the electronic structure and mechanisms responsible for desorption of hydrogen from Ti doped and vacancy containing sodium-alanate (NaAlH4). The energy necessary to remove a hydrogen atom from Ti doped NaAlH4 is significantly smaller than that from pristine NaAlH4 irrespective of whether Ti substitutes the Na or the Al site. However, the presence of Na and Al vacancies is shown to play an even more important role: The removal of hydrogen associated with both Na and Al vacancies is found to be exothermic. It is suggested that this role of vacancies can be exploited in the design and synthesis of complex light metal hydrides suitable for hydrogen storage.

scholarly journals Native point defects in CuIn1−xGaxSe2: hybrid density functional calculations predict the origin of p- and n-type conductivity

2014 ◽  
Vol 16 (40) ◽  
pp. 22299-22308 ◽  
Author(s):  
J. Bekaert ◽  
R. Saniz ◽  
B. Partoens ◽  
D. Lamoen
Keyword(s):  
Charge Carrier ◽  
Point Defects ◽  
First Principles ◽  
Density Functional Calculations ◽  
Density Functional ◽  
First Principles Calculations ◽  
Photoluminescence Spectra ◽  
Type Conductivity ◽  
Native Point Defects ◽  
Hybrid Density Functional

Starting from first-principles calculations, many experimental observations such as photoluminescence spectra, charge carrier densities and freeze-out can be explained.

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