scholarly journals Vacancy Defects in Ga2O3: First-Principles Calculations of Electronic Structure

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7384
Author(s):  
Abay Usseinov ◽  
Zhanymgul Koishybayeva ◽  
Alexander Platonenko ◽  
Vladimir Pankratov ◽  
Yana Suchikova ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Type Conductivity ◽  
Deep Donor ◽  
P Type ◽  
Isolated Point

First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2O3 crystals. Hybrid exchange–correlation functional B3LYP within the density functional theory and supercell approach were successfully used to simulate isolated point defects in β-Ga2O3. Based on the results of our calculations, we predict that an oxygen vacancy in β-Ga2O3 is a deep donor defect which cannot be an effective source of electrons and, thus, is not responsible for n-type conductivity in β-Ga2O3. On the other hand, all types of charge states of gallium vacancies are sufficiently deep acceptors with transition levels more than 1.5 eV above the valence band of the crystal. Due to high formation energy of above 10 eV, they cannot be considered as a source of p-type conductivity in β-Ga2O3.

First-principles study of static displacements in Fe-Pd magnetic shape-memory alloys

2009 ◽  
Vol 1200 ◽  
Author(s):  
Markus E. Gruner
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloys ◽  
Functional Theory ◽  
Lennard Jones ◽  
Theory Comparison

AbstractThis contribution reports static ionic displacements in ferromagnetic disordered Fe70Pd30 alloys obtained by relaxation of the ionic positions of a 108-atom supercell within the framework of density functional theory. Comparison with a simple statistical model based on Lennard-Jones pair interactions reveals that these displacements are significantly larger than can be explained by the different sizes of the elemental constituents. The discrepancies are presumably related to collective displacements of the Fe atoms. Corresponding distortions are experimentally observed for ordered Fe3Pt and predicted by first-principles calculations for all ordered Fe-rich L12 alloys with Ni group elements and originate from details of the electronic structure at the Fermi level.

First-principles insights into ammonia decomposition on MoN (0001) surface

2021 ◽  
Author(s):  
kun yuan ◽  
pengju hao ◽  
Xiaolin Li ◽  
Yang Zhou ◽  
jiangbo zhang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Surface Energy ◽  
Geometric Structure ◽  
First Principles ◽  
Density Functional ◽  
Slab Model ◽  
Ammonia Adsorption ◽  
Functional Theory ◽  
Dehydrogenation Mechanism

Density functional theory (DFT) and periodic slab model were used to study the geometric structure, electronic structure and dehydrogenation mechanism of ammonia adsorption on MoN (0001) surface. The surface energy...

Tunable electronic structure and magnetic moment in C2N nanoribbons with different edge functionalization atoms

2017 ◽  
Vol 19 (23) ◽  
pp. 15021-15029 ◽  
Author(s):  
Yusheng Wang ◽  
Nahong Song ◽  
Min Jia ◽  
Dapeng Yang ◽  
Chikowore Panashe ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Magnetic Moment ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

First principles calculations based on density functional theory were carried out to study the electronic and magnetic properties of C2N nanoribbons (C2NNRs).

A STUDY ON STRAIN AFFECTING ELECTRONIC STRUCTURE OF WURTZITE ZnO BY FIRST PRINCIPLES

2009 ◽  
Vol 23 (19) ◽  
pp. 2339-2352 ◽  
Author(s):  
LI BIN SHI ◽  
SHUANG CHENG ◽  
RONG BING LI ◽  
LI KANG ◽  
JIAN WEI JIN ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Structure ◽  
Valence Band ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
Electron Density Difference ◽  
Different Strains

Density of states and band structure of wurtzite ZnO are calculated by the CASTEP program based on density functional theory and plane-wave pseudopotential method. The calculations are carried out in axial and unaxial strains, respectively. The results of density of states in different strains show that the bottom of the conduction band is always dominated by Zn 4s, and the top of valence band is always dominated by O 2p. The variation of the band gap calculated from band structure is also discussed. In addition, p-d repulsion is used in investigating the variation of the top of the valence band in different strains and the results can be verified by electron density difference.

A MOLECULAR DIODE BASED ON CONJUGATED CO-OLIGOMERS

2006 ◽  
Vol 05 (04n05) ◽  
pp. 535-540
Author(s):  
PING BAI ◽  
CHEE CHING CHONG ◽  
ER PING LI ◽  
ZHIKUAN CHEN
Keyword(s):  
Density Functional Theory ◽  
Spatial Orientation ◽  
First Principles ◽  
Density Functional ◽  
Infinite System ◽  
Energy Gap ◽  
Functional Theory ◽  
Molecular Diode ◽  
Current Voltage ◽  
P Type

A molecular diode based on a conjugated co-oligomer composed of p-type and n-type segments is investigated using the first principles method. The co-oligomer is connected to Au electrodes to form an Au –oligomer– Au system. The infinite system is dealt with a finite structure confined in a device region and effects from semi-infinite electrodes. Density functional theory and nonequilibrium Green's function are used to describe the device region self-consistently. The current–voltage (I–V) characteristics of the constructed system are calculated and a rectification behavior is observed. The energy gap and the spatial orientation of molecular orbitals, and the transmission functions are calculated to analyze the I–V characteristics of the molecular diode.

ELECTRONIC STRUCTURE OF K0.8Fe2Se2 FROM DENSITY FUNCTIONAL THEORY GW METHOD SIMULATION

2013 ◽  
Vol 27 (15) ◽  
pp. 1362017
Author(s):  
LIUXI TAN ◽  
RUI GUO ◽  
SHIZHONG YANG ◽  
EBRAHIM KHOSRAVI ◽  
GUANG-LIN ZHAO ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Electric Dipole ◽  
First Principles ◽  
Density Functional ◽  
Lattice Distortion ◽  
The Novel ◽  
Functional Theory ◽  
Density Analysis ◽  
Iron Based

First principles density functional theory — based (GW) method — was used to simulate the electronic structure of the novel iron-based superconductor K 0.8 Fe 2 Se 2. The calculated band gap of K 0.8 Fe 2 Se 2 at the Γ point is 0.15 eV, which is significantly lower than the 0.61 eV of vacancy free crystal KFe 2 Se 2. The d-orbital of Fe atom is overlapped with the p-orbital of Se atom. Charge density analysis shows strong lattice distortion and vacancy related electric dipole and quadruple near the K vacancy. The reflectivity is anisotropic in three coordinate directions.

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.

Graphene sheet with periodic vacancy: A first principles study

2021 ◽  
Author(s):  
Deepti Maikhuri ◽  
Jaiparkash Jaiparkash ◽  
Haider Abbas
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Graphene Sheet ◽  
First Principles ◽  
Density Functional ◽  
Computational Analysis ◽  
Functional Theory ◽  
First Principles Study

Abstract We present a comprehensive first-principles study of the electronic structure of graphene sheet with periodic vacancy. We report the structural, electronic, and magnetic properties of the graphene sheet with periodic vacancy that possess 48 C & 28 H atoms. Computational analysis based on density functional theory predicts that the periodic vacancy can modulate the properties of graphene sheet. Results show that periodic vacancies lead to the manipulation of band gap & could be utilized to tailor the electronic properties of the sheet. Also, it is found that, the graphene sheet with periodic vacancy is non-magnetic in nature.

scholarly journals Strain and electric field tunable electronic structure of buckled bismuthene

RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 39546-39555 ◽  
Author(s):  
Ming-Yang Liu ◽  
Yang Huang ◽  
Qing-Yuan Chen ◽  
Ze-Yu Li ◽  
Chao Cao ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Electric Field ◽  
First Principles ◽  
Density Functional ◽  
Single Layer ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Functional Theory

Based on first-principles density functional theory calculations, we systemically study the properties of two-dimensional buckled single-layer bismuth (b-bismuthene).

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