scholarly journals Computational Investigation of the Electronic and Optical Properties of Planar Ga-Doped Graphene

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nicole Creange ◽  
Costel Constantin ◽  
Jian-Xin Zhu ◽  
Alexander V. Balatsky ◽  
Jason T. Haraldsen
Keyword(s):  
Band Structure ◽  
Electron Density ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Impurity Scattering ◽  
Hole Doping ◽  
Electronic Band ◽  
Doped Graphene ◽  
Impurity Doping

We simulate the optical and electrical responses in gallium-doped graphene. Using density functional theory with a local density approximation, we simulate the electronic band structure and show the effects of impurity doping (0–3.91%) in graphene on the electron density, refractive index, optical conductivity, and extinction coefficient for each doping percentage. Here, gallium atoms are placed randomly (using a 5-point average) throughout a 128-atom sheet of graphene. These calculations demonstrate the effects of hole doping due to direct atomic substitution, where it is found that a disruption in the electronic structure and electron density for small doping levels is due to impurity scattering of the electrons. However, the system continues to produce metallic or semimetallic behavior with increasing doping levels. These calculations are compared to a purely theoretical 100% Ga sheet for comparison of conductivity. Furthermore, we examine the change in the electronic band structure, where the introduction of gallium electronic bands produces a shift in the electron bands and dissolves the characteristic Dirac cone within graphene, which leads to better electron mobility.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF LuPd2Si2

2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Spin Orbit Coupling ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Scheme

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.

Electronic Band Structure of Cubic Silicon Carbide Nanowires

2008 ◽  
Vol 600-603 ◽  
pp. 575-578 ◽  
Author(s):  
A. Miranda ◽  
A. Estrella Ramos ◽  
M. Cruz Irisson
Keyword(s):  
Silicon Carbide ◽  
Band Structure ◽  
Band Gap ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Thickness Variation ◽  
Hydrogen Atoms ◽  
Electronic Band ◽  
Cubic Silicon Carbide

In this work, the effects of the diameter and morphology on the electronic band structure of hydrogenated cubic silicon carbide (b-SiC) nanowires is studied by using a semiempirical sp3s* tight-binding (TB) approach applied to the supercell model, where the Si- and C-dangling bonds on the surface are passivated by hydrogen atoms. Moreover, TB results (for the bulk) are compared with density functional calculations in the local density approximation. The results show that though surface morphology modifies the band gap, the change is more systematic with the thickness variation. As expected, hydrogen saturation induces a broadening of the band gap energy because of the quantum confinement effect.

Electronic, Thermal, and Superconducting Properties of Metal Nitrides (MN) and Metal Carbides (MC) (M=V, Nb, Ta) Compounds by First Principles Studies

2015 ◽  
Vol 70 (9) ◽  
pp. 721-728
Author(s):  
G. Subhashree ◽  
S. Sankar ◽  
R. Krithiga
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Orbital Method ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Transition Elements ◽  
Electronic Density ◽  
Electronic Band

AbstractStructural, electronic, and superconducting properties of carbides and nitrides of vanadium (V), niobium (Nb), and tantalum (Ta) (group V transition elements) have been studied by computing their electronic band structure characteristics. The electronic band structure calculations have been carried out based on the density functional theory (DFT) within the local density approximation (LDA) by using the tight binding linear muffin tin orbital method. The NaCl-type cubic structures of MN and MC (M=V, Nb, Ta) compounds have been confirmed from the electronic total energy minimum of these compounds. The ground state properties, such as equilibrium lattice constant (a0), bulk modulus (B), and Wigner–Seitz radius (S0) are determined and compared with available data. The electronic density of states reveals the metallic nature of the chosen materials. The electronic specific heat coefficient, Debye temperature, and superconducting transition temperature obtained from the band structure results are found to agree well with the earlier reported literature.

scholarly journals DFT COMPUTATION OF THE BAND STRUCTURE AND DENSITY OF STATE FOR ZnO HALITE STRUCTURE USING FHI-aims CODE.

2020 ◽  
Vol 4 (2) ◽  
pp. 490-498
Author(s):  
M. A. Adamu ◽  
K. Lawal ◽  
K. Lawal ◽  
A. Saminu
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Research Work ◽  
Basis Sets ◽  
Band Structure Calculation ◽  
Density Of State ◽  
Electronic Band

This research work is on Density Functional Theory (DFT) within Local Density Approximation as parameterised by Perdew and Wang (pw-lda).The calculation was performed using Fritz Haber Institute Ab-initio Molecular Simulations (FHI-aims) code based on numerical atomic-centered orbital basis sets. The electronic band structure, density of state (DOS) and band gap energy were calculated for ZnO compound. The band structure and Density of States (DOS) diagrams are plotted from the calculated equilibrium lattice parameters. The experimentally lattice constant values were used to calculate the minimum total energy. The calculated electronic band structure results show that ZnO (Halite) is an indirect semiconductor with energy band gap of 0.89 eV. Hence, the HOMO is -0.863382 eV at L_symmetry point and LUMO is 0.0239417 eV at ᴦ- point. The DOS energy level within the compound shows considerable high state of electron occupation and the DOS observed around the Fermi level at zero level indicate that it has conducting properties. In general, FHI-aims code has shown better accuracy and prediction of band structure calculation within reasonable computational methods.

ELECTRONIC STRUCTURE, DIELECTRIC AND DYNAMICAL PROPERTIES OF ZINC-BLENDE AlN FROM FIRST PRINCIPLES CALCULATION

2007 ◽  
Vol 21 (26) ◽  
pp. 1775-1784
Author(s):  
HUAN-YOU WANG ◽  
HUI XU ◽  
JIAN-RONG XIAO ◽  
MINGJUN LI
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Lattice Parameter ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Plane Wave Method ◽  
Zinc Blende

We have performed density-functional perturbation calculation for zinc-blende AlN using the pseudopotential plane-wave method. The results obtained using both the local-density approximate (LDA) and the generalized-gradient approximate (GGA) for exchange-correlation functional are compared. The ground state properties and response function properties for zinc-blende AlN , including the electronic band structure, charge density, Born effective charge, dielectric constant and vibrational properties are reported. Our results are basically in agreement with experimental data and theoretical values available, but the bandgap is underestimated and the first optical mode in the phonon band structure is overestimated. This can be attributed to the underestimation of the lattice parameter and selection of the pseudopotential.

Ab initio calculation on the Optical Properties of AA- Stacked two dimensional Graphene, Silicene, Germanene, and Stanene

2018 ◽  
Vol 1 (1) ◽  
pp. 46-50
Author(s):  
Rita John ◽  
Benita Merlin
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Complex Refractive Index ◽  
Single Layer ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Wide Range ◽  
Optical Region

In this study, we have analyzed the electronic band structure and optical properties of AA-stacked bilayer graphene and its 2D analogues and compared the results with single layers. The calculations have been done using Density Functional Theory with Generalized Gradient Approximation as exchange correlation potential as in CASTEP. The study on electronic band structure shows the splitting of valence and conduction bands. A band gap of 0.342eV in graphene and an infinitesimally small gap in other 2D materials are generated. Similar to a single layer, AA-stacked bilayer materials also exhibit excellent optical properties throughout the optical region from infrared to ultraviolet. Optical properties are studied along both parallel (||) and perpendicular ( ) polarization directions. The complex dielectric function (ε) and the complex refractive index (N) are calculated. The calculated values of ε and N enable us to analyze optical absorption, reflectivity, conductivity, and the electron loss function. Inferences from the study of optical properties are presented. In general the optical properties are found to be enhanced compared to its corresponding single layer. The further study brings out greater inferences towards their direct application in the optical industry through a wide range of the optical spectrum.

FIRST PRINCIPLE CALCULATION OF ELECTRONIC BAND STRUCTURE AND OPTICAL PROPERTIES OF KIO3

2009 ◽  
Vol 23 (10) ◽  
pp. 2405-2412
Author(s):  
HARUN AKKUS ◽  
BAHATTIN ERDINC
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Functional Methods ◽  
A Value ◽  
Direct Band

The electronic band structure and optical properties of the ferroelectric single crystal KIO 3 have been investigated using the density functional methods. The calculated band structure for KIO 3 evidences that the crystal has a direct band gap with a value of 2.83 eV. The structural optimization has been performed. The real and imaginary parts of dielectric function, energy-loss function for volume and surface, and refractive index are calculated along the crystallographic axes.

Structural, electronic and elastic properties of the B2-ScM (M =Au, Hg and Tl) intermetallic compounds: Ab initio calculations

2015 ◽  
Vol 04 (04) ◽  
pp. 1550020
Author(s):  
Ahmad A. Mousa ◽  
Jamil M. Khalifeh
Keyword(s):  
Mechanical Properties ◽  
Bulk Modulus ◽  
Intermetallic Compounds ◽  
Elastic Constants ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic Band

Structural, electronic, elastic and mechanical properties of ScM (M[Formula: see text][Formula: see text][Formula: see text]Au, Hg and Tl) intermetallic compounds are studied using the full potential-linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation (GGA) and the local density approximation (LDA) to the exchange-correlation approximation energy as implemented in the Wien2k code. The ground state properties including lattice parameters, bulk modulus and elastic constants were all computed and compared with the available previous theoretical and experimental results. The lattice constant was found to increase in contrast to the bulk modulus which was found to decrease with every substitution of the cation (M) starting from Au till Tl in ScM. Both the electronic band structure and density-of-states (DOS) calculations show that these compounds possess metallic properties. The calculated elastic constants ([Formula: see text], [Formula: see text] and [Formula: see text] confirmed the elastic stability of the ScM compounds in the B2-phase. The mechanical properties and ductile behaviors of these compounds are also predicted based on the calculated elastic constants.

Electronic band structure of silver low-index surfaces: a tight-binding study

2020 ◽  
Vol 98 (5) ◽  
pp. 488-496
Author(s):  
H.J. Herrera-Suárez ◽  
A. Rubio-Ponce ◽  
D. Olguín
Keyword(s):  
Band Structure ◽  
Density Of States ◽  
Electronic Band Structure ◽  
Local Density ◽  
Tight Binding ◽  
Theoretical Data ◽  
Binding Study ◽  
Local Density Of States ◽  
Electronic Band ◽  
Tight Binding Method

We studied the electronic band structure and corresponding local density of states of low-index fcc Ag surfaces (100), (110), and (111) by using the empirical tight-binding method in the framework of the Surface Green’s Function Matching formalism. The energy values for different surface and resonance states are reported and a comparison with the available experimental and theoretical data is also done.

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